Date   

Re: Humanity!

Jerry McCarthy
 

Curt Herzstark's autobiography (written in German, English translation available from the OS) I think ticks some of the boxes. I know it's not exactly about SRs, but close enough perhaps.

Regards, Jerry McCarthy, U.K.


On Jun 15, 2021, at 2:54 PM, Rod Lovett <Rod@...> wrote:

Hi All,

I have a fairly small collection of Slide Rule Books

By my computer at this moment there are:

Books by Peter Hopp,
    Slide Rules, Their History Models and Makers; Joint Slide Rules; Pocket Watch Slide Rules

Books by Karl Kleine, 
    The Proceedings of IM2013 and IM2017

A Book by   Kleine and Kuhn  
    Dennert & Pape  Aristo 1872 - 1978

A Book by Barnes and White, 
    Otis King Calculators

A Book Dieter von Jezierski 
    A Journey Through Three Centuries

A Book by Peter Holland 
    Rechenschieber, Slide Rules  A.W. Faber

A Book by Panagiotis Venetsianos 
    Pocketbook of the Gauge Marks

A Book by Ijzebrand Scuitema and Otto van Poelje
    The Schuitema Collection

and others scattered around elsewhere.


They are a glorious mine of information and they all have the same thing in common.  They're about slide rules!

But with one exception* they all lack the same thing.  To a great extent they lack humanity - the human side of the story.

I'm not blaming the authors. This is not their  fault.  It was never part of their brief to include it.

But a book that would appeal to the non-slide rule enthusiast; to the "general public", needs humanity.

Think about making timepieces more accurate.  Be honest! Fairly boring!  The problems with making such timepieces more accurate whilst at sea. Still fairly boring.  Insert the reasons why this is important.  Much less boring.  Insert a self-taught genius and his battle against the establishment and you have "Longitude" and a best seller.

Perhaps that is what is required to keep the slide rule flame alive and interest a new generation of collectors; to tie real people into some real life problems with their use of the slide rule.

Just a thought.

Rod

* P.S.  The one exception:  Calculating on Slide Rule and Disc "2 x 3 .... approximately 6"    by Schuitema and Van Herwijnen  which includes several written portraits of 'slide rule people' mainly from the Netherlands.  However, these portraits are not tied together into one consistent  story. And again that was never the intention.

In one of these Pg 133 the authors say "Sometimes you find a special slide rule and after studying its use and construction you discover that the person behind the object is much more interesting than the slide rule itself". 


Forster's 1632 Dedication to an Oughtred Book with Implications for Slide Rule History

Tom and Lu Wetmore
 

There has been debate over the invention of the slide rule for centuries.

Evidence that Wm. Oughtred was the inventor comes from the dedication Wm. Forster wrote for "The Circles of Proportion and the Horizontal Instrument," first published in 1632. The author on the title page is Forster, though in E.G.R. Taylor's "The Mathematical Practitioners of Tudor and Stewart England, 1486-1714", Oughtred is given author credit while Forster is listed as translator.

Here is the relevant quote from Forster's dedication, which places Oughtred's inventions back into the middle or late 1620s. Let me first point out that the Horizontal Instrument mentioned in the title IS NOT the linear slide rule. I have added a discussion after the quote to clarify that.

Start of quote:

"For being in the time of the long vacation 1630, in the country, at the house of the reverend, and my most worthy friend, and teacher, Mr. William Oughtred (to whose instruction I owe both my initiation, and whole progress in these sciences).

I upon occasion of speech told him of a ruler of numbers, sines and tangents, which one had bespoken to be made (such as is usually called Mr. Gunter’s Ruler) six feet long, to be used with a pair of beam-compasses.

He answered that was a poor invention, and the performance very troublesome: ‘But’, said he, ‘seeing you are taken with such mechanical ways of instruments, I will show you what devices I have had by me THESE MANY YEARS [my emphasis].’

AND FIRST, HE BROUGHT TO ME TWO RULERS OF THAT SORT, TO BE USED BY APPLYING ONE TO THE OTHER, WITHOUT ANY COMPASSES [my emphasis--this is in my opinion the origin story of the linear slide rule]; and after that he showed me those lines cast into a circle or ring, with another, moveable circle upon it.

I seeing the great expedience of both those ways, but especially of the latter, wherein it far excels any other instrument which has been known; told him, I wondered that he could so many years conceal such useful inventions, not only from the world, but from myself, to whom in other parts and mysteries of art, he had been so liberal.

He answered that the true way of art is not by instruments, but by demonstration; and that it is a preposterous course of vulgar teachers, to begin with instruments, and not with the sciences, and so instead of artists, to make their scholars only doers of tricks, and as it were jugglers; to the despite of art, loss of precious time, and betraying of willing and industrious wits, unto ignorance and idleness. That the use of instruments is indeed excellent, if a man be an artist: but contemptible, being set and opposed to art. And lastly, that he meant to commend to me the skill of instruments, but first he would have me well instructed in the sciences.

He also showed me many notes, and rules for the use of those circles, and of his horizontal instrument (which he had projected about 30 years before), the most part written in Latin. All which I obtained of him leave to translate into English, and make public, for the use, and benefit of such as were studious, and lovers of these excellent sciences."

End of quote.

Discussion:

The horizontal instrument mentioned in the book's title, and in the last part of the dedication, is NOT the "two rulers of that sort" mentioned earlier in the dedication. That is, the horizontal instrument is not a linear slide rule. However, the two rulers mentioned were a linear slide rule. The rulers were Gunter's rulers with the log scales of numbers, sines and tangents etched on them. I assume they had square cross-sections with a different scale on each face/edge. The horizontal instrument was an entirely different device that Oughtred had invented many years earlier that had nothing to do with logarithms. It was a tool with astronomical, navigational, and time keeping scales.

The dedication implies to me that at this early stage the circular slide rule was the dominant form. Much of the Oughtred/Delamain debate is based on differing designs for circular slide rules, and on which design is best, and who developed theirs first. When Oughtred showed Forster the "two rulers of that sort", he showed how calculation could be done by sliding two logarithmic rulers against one another without compasses, but he soon put those away and brought out his circular side rule, which is the form stressed thereafter.

I conclude that Oughtred did not think that the linear slide rule made from two Gunter's rulers was all that important. This might be hard for us sliderule fanatics to come to grips with, but I'm afraid it was true. Circular slide rules was where it was at for a long time.

It could be that Oughtred showing Forster how to slide two Gunter's rulers against one another was a very early demonstrations of how the future of linear sliderules would unfold. (I still contend that Gunter himself must have known his rulers could be used in this way.)

There exist examples of circular slide rules made by Oughtred (designed by him, fabricated by Elias Allen), but there are no linear slide rules I know of. I have pictures I can supply to those interested.

I believe this evidence points to Oughtred inventing the circular slide rule around 1627, and knowing at the same time that two Gunter's rulers could be used together without compasses.

Tom Wetmore


Re: 1638 Letter from Oughtred to Allen

Tom and Lu Wetmore
 

Andreas,

I appreciate the work you have done searching through the original documents. We both seem to have that need. I have copies of most of the sources and reread them every year or so, and then ponder once again what was happening in the 1620s and 30s. Not just Oughtred and Delamain, but Briggs and Gunter too. In my opinion Gunter is the unsung hero of the whole bunch. He was the true discoverer and father of the three main slide rule scales. Only his name has stood the test of four centuries and is still found today in Gunter's Rules. As for Oughted and Delamain you and I have opposite conclusions. I am in the Oughtred camp. But I don't feel there is enough evidence to justify a serious argument, or at least I don't want to engage in one.

Yes, Oughtred was the author of the Latin version of the "Circles of Proportion and Horizontal Instrument", with Forster the translator. Did you know that in Taylor's book about the mathematical practitioners of Tudor and Stuart England, he did list Oughtred as the author and Forster as translator?

I also believe that the dedication in that book is the earliest good written account that mentions a true linear slide rule. It refers to two rulers with Gunter's scales on them that are used together without compasses. It was written in 1632 based on an eyewitness account that happened in 1630 based on devices that Oughtred had made years earlier. For me it is the key source in understanding the invention of the linear slide rule.

You say we cannot fully understand what Oughtred's 1638 letter is about. Here I disagre. It is instructions to Allen about design details for the cross staff Allen is making. The only thing that brings that letter out of the ordinary and calls it to our attention is the fact that Oughtred wants Allen to put Gunter's three scales on the cross staff. It isn't clear whether Oughtred wanted only one set to be used with compasses, or two sets, one on each part, to be used as a slide rule.

I have read the two tirades that Oughted and Delamain wrote against one another. It is very nasty stuff, difficult to read, and frankly depressing. Delamain's tirade is pretty much all vitriol, while Oughtred's, though also very nasty, has lots of mathematical examples of Delamain's failings that back up his arguments. I score that battle for Oughtred.

Yesterday I wrote another email to post to this group, but held it back because I believe I can get pretty thick-headed and obtuse in the stuff I write. It contains a copy of the part of the Forster's dedication that mentions Oughtred's linear and circular slide rules. Since it is so germain to this discussion, I'll dust it off and send it a little later.

Regards,

Tom Wetmore


Re: Humanity!

Michael Porter
 

Indeed, it is a sliding Gunter - I had the terminology slightly wrong.  There are Hi-res scans of the front and back in the Files section, in a folder called "Gunter". There is no maker's mark, but I'd think the Wine and Ale gallon ticks would argue for British origin, and surely late 18th or quite early 19th century.


Re: Humanity!

Edward Dean Butler
 

Do you have just the slide, or do you have the accompanying rule? Does the rule carry a maker’s name?

Maybe you have what is termed a “sliding Gunter.” Sliding Gunters date back to at least the early 18th century. I do not know if they go as far back as the late 17th century.

E Dean Butler

On Jun 16, 2021, at 12:42 AM, Michael Porter <mporter@...> wrote:

It's a littloff-topic, but I have a Gunter slide that has come down in my family from the late 18th century. Relevant in this context is that the rule originally had SR scales in the C and D positions, but these were scraped off and replaced with douoble and single girt scales with both WG and AG tick marks. Though they are not obvious in the scans (posted inthe Files section), the divider marks where a workman laid out the scales are very clear. It is pleasing to think of the workman who did this, perhaps for a particular owner, perhaps for the marine market in general.


Re: Humanity!

Michael Porter
 

It's a littloff-topic, but I have a Gunter slide that has come down in my family from the late 18th century. Relevant in this context is that the rule originally had SR scales in the C and D positions, but these were scraped off and replaced with douoble and single girt scales with both WG and AG tick marks. Though they are not obvious in the scans (posted inthe Files section), the divider marks where a workman laid out the scales are very clear. It is pleasing to think of the workman who did this, perhaps for a particular owner, perhaps for the marine market in general.


Re: Humanity!

Maynard Wright
 

I really enjoy knowing the history of a few slide rules I have that were labeled with such a distinctive name, on the rule or the case or both, that I was able to track the name down and learn at least a little about the original owner.  I like those rules better than ones that are in factory perfect condition.

Best regards,

Maynard Wright

On 6/15/21 12:14 PM, Andreas Poschinger wrote:
Am 15.06.2021 um 20:06 schrieb Eamonn:
While the paper gets a bit technical in some places, I think the
author did a marvelous job of presenting the human side of the story
behind the development these rules.
Yes, I agree. That was the first "serious" English source, which I've
read on sliderules some two ys. ago. The Delamain and Oughtred papers of
course also have a deep personal side, but difficult to read for me and
not very positive...

I own some few sliderules with personal stories behind. The maybe
deepest is a Faber Electro which I spotted in the net but the price was
too high. I wanted to deal about the proce but the woman selling this
sliderule of his grandfather told me that she would rather donate the
sliderule to somebody that she would sell it to me at a lower price. So
the story was almost over until some months later again I came across
the very same sliderule at the same price. I remebered what she told me
and I decided to phone her. So if she liked to donate it she could
donate it to my university. But I did not come so far. After I sayed
hello at the phone and whether she remembers me she told me that her
grandson, a baby, died today. And I had several phone calls with her not
slide rule related. She eventually has sent me the sliderule and all the
time I see it I remember this story of course. Last time I saw it when
digging for the Electro with the Thornton 144 146 cursor.  Maybe I
should phone her again.

Another far less deep but interesting story is a short Pickett N3 that
I've got from somebody living in East Germany. I've asked him whether he
originally is from the West, but he answered no. Then of course I wanted
to know how this sliderule, which hardly was found in West Germany made
it into German Democratic Republic. And it came out that he got it from
a friend being I believe from Mejico who studied with him I believe at
the Bergschule Eisleben. When he went back home he gave all he did not
need to the guy where I bought it from so that the sliderule stayed in
GDR. It is really the case that when not writuing thise things down and
I am nobody with regular journal, they get lost...

Best regards

Andreas





Re: 1638 Letter from Oughtred to Allen

Andreas Poschinger
 

Hi Tom,

Am 14.06.2021 um 10:49 schrieb Tom and Lu Wetmore via groups.io:
Forster's "The Circles of Proportion and Horizontal Instrument, Both
Invented and the uses of both written in Latin by Mr. W. O. [William
Oughtred], Translated into English and set forth for he publique by
William Forster"
Yes I know it, because it is the only book about Oughtreds dialrule, at
least which really got published, isn't it? But actually it is Oughtreds
book and Forster is the translator only. I'd say that under normal
circumstances the official author of this book would be Oughtred and if
Oughtred would be a nice guy there would be somewhere acknowledgements
for Forster for having translated this book. So that Forster is now the
author actually makes it even suspicious for me - at least I do not
regard it as independent source.

Of course, somebody is lying or has a least a strong and strange
alternative truth, but I'd not say that this is necessarily Delamain.
You may remember where Delamain describes his meeting with Oughtred
before he published the Grammelogia respectively donated the prototype
to the king, and this description reads for me quite objective and
trustable, though of course it is a defense against Oughtred's accuse
that Delamain did not have more than two circles of logarithmic lines
yet (which actually is the very point of a sliderule!). Oughtred however
did - according to Delamain, and I believe him here - not tell anything
about his (Oughtreds) sliderule or instrument. So the only possibility
for me to stay within alternatives thruths and not accusing for mere
lies and given that at that time nobody (but maybe Delamain) could
define a sliderule yet, the most likely for me is that Forster saw the
Dialrule including manual and maybe even some linear sticks, but these
alone actually are no sliderules yet. They get a sliderule when you know
how to use them as sliderule but this is described by Delamain only. And
even if there was something linear, then we do not know at all how it
may have looked like. The only source is the letter to Allen, several ys
after Delamains sliderule and Oughtreds dialrule, and I agree with you,
that it is difficult to say by beyond 90% what it really is about. So
far I remember one yr. back we came to the point that we were even
uncertain whether this drawing really fits the text or whether there
came in some Wingate or whatever stuff, I remember it was confusing.

Indeed, given that Delamain clearly published a sliderule in shape and
use, while we do not know any details from an Oughtred sliderule -
neither shape nor use (not his dialrule!), and given that Delamain
published first (even if very hasty either to not miss the kings
birthday, and/or even to fear that Oughtred may steal his sliderule idea
e.g. by "industrial spying" at Allen), in my opinion it is an unfairness
and even nogo to not acknowledge his merits about sliderule development
placed at a very prominent position in the timeline.

There are of course open questions: One point e.g., why the Grammelogia
evolved quite slowly starting with the basic logarithmic lines only. One
explanation is that he first needed to steal new ideas from Oughtred or
other people again, another may be simply that Delamain was not wealthy
enough so that he could afford new scales only when having money. Of
course this would be somehow embarrasing, so that Delamain would not
have written it. Nevertheless the grammelogia always seemed to have its
huge diameter of two feet (!). So this tells me that Delamain most
likely had at least a clear vision and most likely even a paper model
for what to use the space, even if there were only two logarithmic lines
in the beginning (plus the line of 100000 equal parts which should have
costed already quite a money...).

Best regards

Andreas


Re: Davis-Pletts Rule

Eamonn
 

Hi Bob,

Thanks for the pointer to your LN Scale presentation. I read it and found it to be very comprehensive and well written.

I especially appreciated the details regarding the gauge marks on the rule proposed by Cohen for evaluating exponentials with powers greater than 2.3. I do think that the proposed gauge marks would have made such calculations easier than finding the exponent modulo 2.3026, but the procedure still seems a bit cumbersome. On the Davis-Pletts rule, the larger range of the LN scale allows exponentials with powers up to 9.2 to be evaluated directly, at the expense of occupying more scale real estate.

There is one additional interesting detail on the Davis-Pletts Ln scale that is discussed in Pletts' patent. The top part of the Ln scale has a range of 0 to 4.6 and the bottom part has a range of 4.6 to 9.2. However, ln(100) is actually 4.605..., so the tick marks on the bottom part of the scale are offset by 0.005 from the correct values. This is half the distance between the tick marks, so it is definitely noticeable.

In the patent Pletts references a line/gauge mark labeled 'l' equal to the distance between 4.6 and 4.605 at each end of the scale to correct for this offset. I see a line in the appropriate position at the left end of the Ln scale in the photos uploaded by Alan. Looks like there may be also a line on the right end of the scale, but the picture is not so clear. There does seem to be a small '1' which I interpret as an 'l' indicator on the right end, but not on the left end.

Eamonn.


Re: Humanity!

Edward Dean Butler
 

I am sure Rod Lovett will publish stories such as the interesting N3 story in Skid Stick.

Many of us enjoy reading these stories!

E Dean Butler

On Jun 15, 2021, at 8:14 PM, Andreas Poschinger <andreas.poschinger@gmx.net> wrote:

Am 15.06.2021 um 20:06 schrieb Eamonn:
While the paper gets a bit technical in some places, I think the
author did a marvelous job of presenting the human side of the story
behind the development these rules.
Yes, I agree. That was the first "serious" English source, which I've
read on sliderules some two ys. ago. The Delamain and Oughtred papers of
course also have a deep personal side, but difficult to read for me and
not very positive...

I own some few sliderules with personal stories behind. The maybe
deepest is a Faber Electro which I spotted in the net but the price was
too high. I wanted to deal about the proce but the woman selling this
sliderule of his grandfather told me that she would rather donate the
sliderule to somebody that she would sell it to me at a lower price. So
the story was almost over until some months later again I came across
the very same sliderule at the same price. I remebered what she told me
and I decided to phone her. So if she liked to donate it she could
donate it to my university. But I did not come so far. After I sayed
hello at the phone and whether she remembers me she told me that her
grandson, a baby, died today. And I had several phone calls with her not
slide rule related. She eventually has sent me the sliderule and all the
time I see it I remember this story of course. Last time I saw it when
digging for the Electro with the Thornton 144 146 cursor. Maybe I
should phone her again.

Another far less deep but interesting story is a short Pickett N3 that
I've got from somebody living in East Germany. I've asked him whether he
originally is from the West, but he answered no. Then of course I wanted
to know how this sliderule, which hardly was found in West Germany made
it into German Democratic Republic. And it came out that he got it from
a friend being I believe from Mejico who studied with him I believe at
the Bergschule Eisleben. When he went back home he gave all he did not
need to the guy where I bought it from so that the sliderule stayed in
GDR. It is really the case that when not writuing thise things down and
I am nobody with regular journal, they get lost...

Best regards

Andreas







Re: Humanity!

Andreas Poschinger
 

Am 15.06.2021 um 20:06 schrieb Eamonn:
While the paper gets a bit technical in some places, I think the
author did a marvelous job of presenting the human side of the story
behind the development these rules.
Yes, I agree. That was the first "serious" English source, which I've
read on sliderules some two ys. ago. The Delamain and Oughtred papers of
course also have a deep personal side, but difficult to read for me and
not very positive...

I own some few sliderules with personal stories behind. The maybe
deepest is a Faber Electro which I spotted in the net but the price was
too high. I wanted to deal about the proce but the woman selling this
sliderule of his grandfather told me that she would rather donate the
sliderule to somebody that she would sell it to me at a lower price. So
the story was almost over until some months later again I came across
the very same sliderule at the same price. I remebered what she told me
and I decided to phone her. So if she liked to donate it she could
donate it to my university. But I did not come so far. After I sayed
hello at the phone and whether she remembers me she told me that her
grandson, a baby, died today. And I had several phone calls with her not
slide rule related. She eventually has sent me the sliderule and all the
time I see it I remember this story of course. Last time I saw it when
digging for the Electro with the Thornton 144 146 cursor.  Maybe I
should phone her again.

Another far less deep but interesting story is a short Pickett N3 that
I've got from somebody living in East Germany. I've asked him whether he
originally is from the West, but he answered no. Then of course I wanted
to know how this sliderule, which hardly was found in West Germany made
it into German Democratic Republic. And it came out that he got it from
a friend being I believe from Mejico who studied with him I believe at
the Bergschule Eisleben. When he went back home he gave all he did not
need to the guy where I bought it from so that the sliderule stayed in
GDR. It is really the case that when not writuing thise things down and
I am nobody with regular journal, they get lost...

Best regards

Andreas


Re: Humanity!

Eamonn
 

The Bill Robinson paper on Mendell Weinbach and the development of the 4093/4083 slide rules is the best example of a human interest slide rule story that I am aware of.

Fortunately, Weinbach maintained a copy of all his correspondence with K&E and his family donated his professional papers to the University of Missouri. He also kept one of the test/prototype rules that were used to evaluate different scale layouts. The 60 page paper is based on 660 pages of material from the Weinbach archive, without which the story could not have been told. While the paper gets a bit technical in some places, I think the author did a marvelous job of presenting the human side of the story behind the development these rules.


Re: Humanity!

Alan Williams
 

I agree with the sentiment that "Sometimes you find a special slide rule and after studying its use and construction you discover that the person behind the object is much more interesting than the slide rule itself". This is exactly what happened in the last few days after my post about the Davis-Pletts rule, having been prompted to look into the life of its originator, John St. Vincent Pletts. I'm sure his short but eventful 44-year life would make a gripping read.

A similar episode occurred a few years ago when I was just starting my collection and purchased a couple of special-purpose slide rules for calculating the perforation of Firth-Brown's armour plate by "Tresidder's formula", having long been interested in Sheffield's steel industry. On receiving them I noticed that, although basically pristine, both rules were covered in faint pencil notes and numbers which I considered gently removing with a soft eraser, but for some reason never got around to doing.

A few weeks later, I noticed that the same seller had auctioned several other unusual devices including a complicated-looking angle measuring tool with a patent marking. This also turned out to be the invention of a Captain Tresidder, so I contacted the seller to find out where the items had originated. It turned out that they all came from the effects of Captain Tolmie John Tresidder, another fascinating figure with a long and illustrious career in the steel industry. The development of naval armour and the projectiles designed to penetrate it were almost the space race of the early 20th century, culminating in the First World War. The slide rules had been Tresidder's own working examples that he annotated with additional figures and notes, having originally accompanied a manuscript of a speech that he had given on the subject of armour plate (which unfortunately I was unable to reunite with the rules).

Suffice to say I have never been so pleased not to have cleaned a slide rule, an ethos I continue to live by.


Re: Humanity!

Edward Dean Butler
 

Rod makes a very interesting observation.

Personally, I very much enjoy the human element connected with old slide rules — the stories about Bate, Watt, etc.

But there is precious little such information.

My other hobby is old race cars (for which my wife has declared me too old).  The literature about old race cars is very much oriented to the human factors — making the hobby a lot more interesting. The recent, popular movie Ford v Ferrari is a case in point. The cars actually take a back seat to the people.

Dean


On Jun 15, 2021, at 2:54 PM, Rod Lovett <Rod@...> wrote:

Hi All,

I have a fairly small collection of Slide Rule Books

By my computer at this moment there are:

Books by Peter Hopp,
    Slide Rules, Their History Models and Makers; Joint Slide Rules; Pocket Watch Slide Rules

Books by Karl Kleine, 
    The Proceedings of IM2013 and IM2017

A Book by   Kleine and Kuhn  
    Dennert & Pape  Aristo 1872 - 1978

A Book by Barnes and White, 
    Otis King Calculators

A Book Dieter von Jezierski 
    A Journey Through Three Centuries

A Book by Peter Holland 
    Rechenschieber, Slide Rules  A.W. Faber

A Book by Panagiotis Venetsianos 
    Pocketbook of the Gauge Marks

A Book by Ijzebrand Scuitema and Otto van Poelje
    The Schuitema Collection

and others scattered around elsewhere.


They are a glorious mine of information and they all have the same thing in common.  They're about slide rules!

But with one exception* they all lack the same thing.  To a great extent they lack humanity - the human side of the story.

I'm not blaming the authors. This is not their  fault.  It was never part of their brief to include it.

But a book that would appeal to the non-slide rule enthusiast; to the "general public", needs humanity.

Think about making timepieces more accurate.  Be honest! Fairly boring!  The problems with making such timepieces more accurate whilst at sea. Still fairly boring.  Insert the reasons why this is important.  Much less boring.  Insert a self-taught genius and his battle against the establishment and you have "Longitude" and a best seller.

Perhaps that is what is required to keep the slide rule flame alive and interest a new generation of collectors; to tie real people into some real life problems with their use of the slide rule.

Just a thought.

Rod

* P.S.  The one exception:  Calculating on Slide Rule and Disc "2 x 3 .... approximately 6"    by Schuitema and Van Herwijnen  which includes several written portraits of 'slide rule people' mainly from the Netherlands.  However, these portraits are not tied together into one consistent  story. And again that was never the intention.

In one of these Pg 133 the authors say "Sometimes you find a special slide rule and after studying its use and construction you discover that the person behind the object is much more interesting than the slide rule itself". 


Re: Humanity!

Karl Kleine
 

True enough, Rod!

Yet, there is a bit more available than you think, though not at the length of a novel.

The first one may be language problem, as it's written in German, not English.
It is the chapter "Meine Zeit bei Dennert & Pape" by Harry Stille (my time at D&P),
pages 44-65 in the ARISTO book by KLaus Kühn and me.

The second is an attempt by IJzebrand Schuitema. He wrote a 100 page memoir,
"The Slide Rule as a Hooby Theme", and tried to make people write similar reports
about their life with slide rules to make a book out of these. That never happened,
all that remained was his book. I do not the sequence of events, if his book came
first, then the attempt to find people joining him, or his plea and then his book,
after no/insufficient response.

Anyhow, we should raise that issue at IM2021, and anybody who wants to contribute
to the discussion is asked to write me position paper, which I would publish with the
proceedings. Or you make a (brief) presentation at IM2021. [see www.im2021.org]

Rod, we should also have a private ZOOM talk, maybe tonight?

Karl

____________________________________________________________________________
Prof. Karl Kleine - c/o Ernst-Abbe-Hochschule Jena, Germany - karl.kleine@eah-jena.de

________________________________________
Von: sliderule@groups.io <sliderule@groups.io> im Auftrag von Rod Lovett <rod@lovett.com>
Gesendet: Dienstag, 15. Juni 2021 15:54
An: sliderule@groups.io
Betreff: [sliderule] Humanity!

Hi All,

I have a fairly small collection of Slide Rule Books

By my computer at this moment there are:

Books by Peter Hopp,
Slide Rules, Their History Models and Makers; Joint Slide Rules; Pocket Watch Slide Rules

Books by Karl Kleine,
The Proceedings of IM2013 and IM2017

A Book by Kleine and Kuhn
Dennert & Pape Aristo 1872 - 1978

A Book by Barnes and White,
Otis King Calculators

A Book Dieter von Jezierski
A Journey Through Three Centuries

A Book by Peter Holland
Rechenschieber, Slide Rules A.W. Faber

A Book by Panagiotis Venetsianos
Pocketbook of the Gauge Marks

A Book by Ijzebrand Scuitema and Otto van Poelje
The Schuitema Collection

and others scattered around elsewhere.


They are a glorious mine of information and they all have the same thing in common. They're about slide rules!

But with one exception* they all lack the same thing. To a great extent they lack humanity - the human side of the story.

I'm not blaming the authors. This is not their fault. It was never part of their brief to include it.

But a book that would appeal to the non-slide rule enthusiast; to the "general public", needs humanity.

Think about making timepieces more accurate. Be honest! Fairly boring! The problems with making such timepieces more accurate whilst at sea. Still fairly boring. Insert the reasons why this is important. Much less boring. Insert a self-taught genius and his battle against the establishment and you have "Longitude" and a best seller.

Perhaps that is what is required to keep the slide rule flame alive and interest a new generation of collectors; to tie real people into some real life problems with their use of the slide rule.

Just a thought.

Rod

* P.S. The one exception: Calculating on Slide Rule and Disc "2 x 3 .... approximately 6" by Schuitema and Van Herwijnen which includes several written portraits of 'slide rule people' mainly from the Netherlands. However, these portraits are not tied together into one consistent story. And again that was never the intention.

In one of these Pg 133 the authors say "Sometimes you find a special slide rule and after studying its use and construction you discover that the person behind the object is much more interesting than the slide rule itself".


Humanity!

Rod Lovett
 

Hi All,

I have a fairly small collection of Slide Rule Books

By my computer at this moment there are:

Books by Peter Hopp,
    Slide Rules, Their History Models and Makers; Joint Slide Rules; Pocket Watch Slide Rules

Books by Karl Kleine, 
    The Proceedings of IM2013 and IM2017

A Book by   Kleine and Kuhn  
    Dennert & Pape  Aristo 1872 - 1978

A Book by Barnes and White, 
    Otis King Calculators

A Book Dieter von Jezierski 
    A Journey Through Three Centuries

A Book by Peter Holland 
    Rechenschieber, Slide Rules  A.W. Faber

A Book by Panagiotis Venetsianos 
    Pocketbook of the Gauge Marks

A Book by Ijzebrand Scuitema and Otto van Poelje
    The Schuitema Collection

and others scattered around elsewhere.


They are a glorious mine of information and they all have the same thing in common.  They're about slide rules!

But with one exception* they all lack the same thing.  To a great extent they lack humanity - the human side of the story.

I'm not blaming the authors. This is not their  fault.  It was never part of their brief to include it.

But a book that would appeal to the non-slide rule enthusiast; to the "general public", needs humanity.

Think about making timepieces more accurate.  Be honest! Fairly boring!  The problems with making such timepieces more accurate whilst at sea. Still fairly boring.  Insert the reasons why this is important.  Much less boring.  Insert a self-taught genius and his battle against the establishment and you have "Longitude" and a best seller.

Perhaps that is what is required to keep the slide rule flame alive and interest a new generation of collectors; to tie real people into some real life problems with their use of the slide rule.

Just a thought.

Rod

* P.S.  The one exception:  Calculating on Slide Rule and Disc "2 x 3 .... approximately 6"    by Schuitema and Van Herwijnen  which includes several written portraits of 'slide rule people' mainly from the Netherlands.  However, these portraits are not tied together into one consistent  story. And again that was never the intention.

In one of these Pg 133 the authors say "Sometimes you find a special slide rule and after studying its use and construction you discover that the person behind the object is much more interesting than the slide rule itself". 


Re: Unusual Combination

Andreas Poschinger
 

Thanks Bob, very interesting! Somehow the 144 is really boring
especially compared to the 146B.

Nevertheless a new question with the 144: It seems to be pretty much the
same time as the Darmstadt, and the basic layout principle is quite
identical. Which was first?

The 146B on the first view seems to be somehow a British Hemmi 153 with
Gd scale and differential Hypertrig on Slide. That is really cool! The
only problem I'd see in practical usage is, that for typical complex
calculations the slide needs to be turned in the middle of calculation
while the cursor saves the last value. If once you should have too many
of them I'd be interested... ...maybe it would be also fine without
cursor, if it had the same width as my cursor. Does a manual exist?

Best regards

Andreas



Am 14.06.2021 um 08:10 schrieb Bob Adams:

I have uploaded scans of the PIC 144 and 146 slide rules


Re: 1638 Letter from Oughtred to Allen

Edward Dean Butler
 

Hi KarlL:

As always, your knowledge and scholarship is to be admired!

One thought I have, upon reading your message, is that we tend to think most early “slide rule” development was in England, with movement to France in the early 19th century. Lambert shows the is not really correct.

I do hope you will update your paper — and it would be wonderful if more reproductions could be made.

Dean

On Jun 14, 2021, at 3:15 AM, Karl Kleine <karl.kleine@eah-jena.de> wrote:

Dean,

Lambert wrote a book in 1761, second edition 1772, "Beschreibung und Gebrauch
der logarithmischen Rechenstäbe..." (description and use of logarithmic calculating rods...)
and had them made by Brander in Augsburg. I made replicas and presented both the
paper and the replicas at the IM2006 in Greifswald. Lambert wanted maximum
precision with rods still usable, so he proposed a length of 5 feet. I built two pairs
with 4 feet scales (my practical limit for manufacturing them); I donated one pair to the
computing museum of Greifswald university and still have the second pair.
These are square rods, a logarithmic scale of two cylces, a linear scale (log of the first one),
a sin and a tan scale.

Brander made Lambert's rods. One is known to still exist, but unfortunately only one of a pair.
It's in the Deutsches Museum and came there in a package of a lot of other instruments.
The documentation is inconclusive with respect to the second rod, if only one came to the
museum or if the second one got lost in the turmoil of WWII. I did not know that when I built
my replicas, and so I followed Lambert's idealistic view of practically achievable precision with
the help of a professional large scale precision plotter. I will have to redo the whole thing with
the knowledge of today of Brander's rods, and I have to rewrite the paper, which was in German,
in English.

So, yes, there were slide rules in the form of two independent rods. As there was a request for
a second printing / edition ten years after the first, it looks like there was a need and a market
for them in the second half of the 18th century in Germany. And yes, it looks like Brander also
made shorter versions of them (there are notes to multiples of feets for their length, which
also points to the issue of usual lengths of slide rules, which occured earlier in this forum).

Karl

PS: Whenever I wrote foot / feet above, that refers to an "Ulmer Fuß", which was 29.7 cm.

PS2: I tried to attach a picture of my rods, but that failed. Will send it to you personally, Dean.

____________________________________________________________________________
Prof. Karl Kleine - c/o Ernst-Abbe-Hochschule Jena, Germany - karl.kleine@eah-jena.de

________________________________________
Von: sliderule@groups.io <sliderule@groups.io> im Auftrag von Edward Dean Butler <edeanbutler@gmail.com>
Gesendet: Montag, 14. Juni 2021 03:18
An: sliderule@groups.io
Betreff: Re: [sliderule] 1638 Letter from Oughtred to Allen

With regard to early slide rules that are only two “sticks” that slide one against the other: does anyone know of such slide rules in museums or private collections?

....... rest deleted .............. kl




Re: 1638 Letter from Oughtred to Allen

Tom and Lu Wetmore
 


On Jun 14, 2021, at 1:30 AM, Andreas Poschinger <andreas.poschinger@...> wrote:

Hi Tom,

thanks for clarification. I actually believe that Oughtred describes a slide rule or better sliding sticks here, even if we don't know how it should look like, but I believe that also Oughtred did not really know how they looked like:

"I would gladly see one of them when it is finished: wich yet I never have done."


I can only say maybe. The device in question is a cross staff with log lines. Whether both the staff and the transverse had the same log lines is open to question. I believe the quote only means Oughtred has not yet seen what Allen has done on the device so far. With a single set of log lines the cross staff is usable with compasses. These log lines were all two decades long, making this possible.

This is only one piece of communication between Oughtred and Allen about this device. This letter comes after Allen has already etched some scales. Allen had sent Oughtred impressions of those scales by inking the scales and 'printing' them on paper. Oughtred is sending instructions for follow on work. So we are seeing the cross staff through a small window in the middle of its development. I want to reexamine that printing to see if the log lines are already on it. If they are I think we could assume that the staff already had the log lines and Oughtred is adding them to the transverse. But if so it seems he would have instructed Allen to make them the exact length of the scales on the staff. Since the transverse is shorter than the staff this instruction would be very important.

On the open question whether he described sliding sticks, I interpret this from these sentences:

"The lines of Numbers, Sines, & Tangentes, are to be set on the transversarie, ..." (... where he tells as that these were on Gunters staff)

"The divisions of the line of Latitudes, and of the line of 100 aequal 
parts, on the fourth side of the staffe, must not be sett to the edges (as the –a–
other divisions were) but in the midle, close together..."

This isn't enough for me. I want this cross staff to be usable as a two rod slide rule, but I don't think there is enough evidence here.

So question what are the other divisions? Further for what does he need on both, staff and transversary, 100000 equal parts? Delamain also explains the 100000 equal parts in his I believe it was the 1632 edition respectively addition and there they are used to find the logarithms on the scales out of a 5 or even 6 digit table.


This could imply logarithmic lines, or it could mean that he is helping Allen compute etching locations for other scales by computing locations as parts of 100000. Though I agree this seems most applicable to log lines.

Well, it may not be 90% and even not 70% that he describes here a slide rule respectively sliding sticks, but what would be the novelty of this instrument? And for what that the pinnacles can be easily removed if not for sliding in parallel? So this makes the 90% more likely for me.


As I say, I want this cross staff to be used in this way, and the letter is suggestive of it, but I don't see it as conclusive.

My point somehow is, that under normal circumstances given the dates of publication Delamain has priority, and only due to Oughtreds attacks on Delamain it is taken from him, even after finding his book, including his layout it was not rectified. Delamain refers to Gunter as his teacher, so that at least for me it is likely that when Gunter died Delamain looked for somebody to whom he could speek - as what we could call nowadays "peer reviewer", and Oughtred was this guy. Oughtred for my taste did not want a peer relation but wanted a teacher-student connection to Delamain (maybe being also "theological father"), but obviously Delamain not.


I don't believe this. Have you read Forster's "The Circles of Proportion and Horizontal Instrument, Both Invented and the uses of both written in Latin by Mr. W. O. [William Oughtred], Translated into English and set forth for he publique by William Forster"? In the forward of this book Forster describes his visit with Oughtred in 1630, and that at that time Oughtred showed him both linear and circular slide rules that he had had in his work room for years, and his instructions, written in Latin, for using them, were fully developed by then. For me this puts the invention of the slide rule well back into the 1620s in Oughtred's back room. This is a second source that gives Oughtred priority. I know you believe that priority should go to the person who publishes first, but I am not as firm on that point.

Why should we clarify about history of ST scale, as long as the invention of the sliderule itself, respectively the insight of its usefulness is awarded to somebody who does not proof his priority with one technical detail but with mere attacks and as long as the priority of somebody is taken away from somebody who tried to describe each detail, so that every manufacturer and everybody can create copies of it? Unfortunaltely the problem of the Grammelogia for my understanding were its many scales. In times of manual division it did cost most likely some three times as much as Oughtreds dialrule which explains that none is found anymore.


I believe Oughtred deserves priority. I am not swayed by Delamain. But I concede that there is not enough evidence to prove the inventor. This argument seems similar to the one about who wrote Shakespeare's plays. Maybe we can never know, but we can appreciate that such masterpieces of the English language exist.

Tom Wetmore

Best regards

Andreas


Re: Davis-Pletts Rule

Bob Adams
 

Hi Alan and Eamonn,

 

I once wrote an IM  paper on the Ln scale ( files are in the groups file section) and was completely unaware of the Pletts rule, many thanks for this new info!

BTW a scan of the Westec rule is included in the files

 

Kind regards

Bob

 

From: sliderule@groups.io [mailto:sliderule@groups.io] On Behalf Of Eamonn
Sent: Monday, 14 June 2021 2:32 PM
To: sliderule@groups.io
Subject: Re: [sliderule] Davis-Pletts Rule

 

Hi Alan,


Thanks for the background info on Pletts. I think you may be right on the Davis-Pletts rule being a bit a few years ahead of its time. Given his background and his position at Marconi, Pletts was undoubtedly aware of the advantages that a rule with hyperbolic scales brings to solving complex-valued vector problems. But the communications industry was still in its infancy in the early 1920s. There just may not have been many engineers at the time that would have needed such a rule, and of those, not all may have appreciated its advantages.

There is also a marketing and eduction component that is required to show the benefits and promote adoption of a rule. I suspect that Weinbach's position as a professor was a key reason for the relative success of 4093 and subsequently the 4083. He instructed his own students in the use of the rule and he pushed K&E to promote it among electrical engineering professors at other universities. This provided a ready market for the rule. Pletts' position in industry may have been a disadvantage in that regard. Even so, it took 6 to 7 years after its introduction in 1929 for the annual sales of the 4093 to exceed 1000 units per year. The great depression had an impact on the numbers, but sales grew quite rapidly after that, aided by the onset or WWII.

Thanks for the pointer on the Westech electronics rule with the Ln scale. I was not aware of it previously.

I also find the experimentation taking place in the first part of the 20th century with various bases for log-log scales to be interesting. Do you know which was the first rule to use log to the base e? I know the K&E 4092 used base e, but I don't know if there was an earlier rule to do so. The Yokota uses base 3.5 and the Perry uses base 2.5. I am not familiar with the others you mention. 

As Andreas says, congrats on the Davis-Pletts pickup. Sounds like you have some very interesting rules in your collection.

Eamonn.

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