Hi Rod, I have Overhead Projection Rules by FC and by Aristo in very good conditions and with docs. I have also Classroom Demonstration Ruler by FC, 2 m long. Maciej pt., 12 lut 2021 o 13:45 Rod Lovet

Hi Rod, ,could you estimate the price of FC 2/84 Best regards, Maciej niedz., 24 sty 2021 o 14:45 Rod Lovett <rod@...> napisał(a):

... it follows from: (n + 1)^2 = n*2 + (2n + 1) m śr., 19 sie 2020 o 12:11 Maciej M. Sysło via groups.io <syslo@...> napisał(a):

Hi Gabriel, It was already used by Babbage in his not-finished difference engine that a square of an integer is equal to the square of the previous integer plus a consecutive odd integer. 1^2 = 1 = 0

Any 2/84N available for 50 Euro? Maciej pon., 17 sie 2020 o 22:06 Andreas Poschinger <andreas.poschinger@...> napisał(a):

Dear Andreas, I uploaded two scans of the pamphlet. You can see what kind of problems they were involved in. First, they had to remind themselves that a circle has 360 degrees, an hour has 60 minutes,

Hello Andreas, I uploaded to Trig-Easy folder 3 pictures of other slide-devices for trigonometry. Note, they were designed as educational tools for defence workers; they usually have a hard time with

Hi Andreas, I remember my colleagues at the end of 1960s from a technical university who had to use SRs for calculating their projects in various technical disciplines. I graduated in math from a univ

Hi, here: https://www.ebay.pl/itm/Superbe-machine-a-calculer-de-W-Schickard-1623-rechenmaschine-calculator/324197844052 you can see another replica of Schickard's machine, much cheaper. and I attach a

Fantastic! maciej czw., 12 mar 2020 o 21:14 Rod Lovett <rod@...> napisał(a):

Hi Andreas, I would suggest to initiate two groups: mechanical calculators (like Pascalina) and electronic calculators. I will join the former one. Maciej wt., 29 paź 2019 o 22:41 Andreas Poschinger <