Jaap Scherphuis

@jaapsch.net

154 Followers 206 Following

Mathematician, likes mechanical calculators, twisty puzzles, the Psion II, and tiling patterns. See https://www.jaapsch.net

Mugshots of Wilcox and Cassidy, and a picture of Phillips just before he settled down in Spokane. (2012-07-22 The Spokesman Review, Spokane, Washington)
William R. Phillips says he believes his father was Butch Cassidy. (1987-03-22 The Spokesman Review, Spokane, Washington)
Newspaper article about William T Phillips. He explains that his adding machine can also subtract by going in reverse.
"HANDS - What Are You Doing With Yours?", with the photo of Genevieve Deasy.
Newspaper photo of a woman using a comptometer. The background is inked black, and the edges of the desk and comptometer are accentuated with white ink. There are arrow markings to show the left and right margins to crop to when printing.
Ad asking for young ladies to become Comptometer operators. (1917-11-22 Western Daily Press)
"Machine-Guns in the Office" An ad for the Burroughs Adding Machine, featuring a drawing of a woman behind an office desk, partly hidden behind a large pile of books and handling a machine-gun.
"Machine-Guns in the Office" An ad for the Burroughs Adding Machine, featuring a drawing of a woman behind an office desk, partly hidden behind a large pile of books and handling a machine-gun.
Front cover of The Soldiers' French Phrase Book
Beitannic pinwheel calculator at a fleamarket stall. It was in nice condition except that the clearing of the counter did not work on one number wheel.
Two sets of oven dishes, a black set and a white set, three dishes in each, standing side by side.
Stephenson Adder, type I. A simple brass adding machine, with two dials. It is used to add up a column of digits.
2025 -> 2026
Video from a 1966 office technology exhibition in the Netherlands. It shows someone writing on an Electrowriter, and another Electrowriter reproducing that exactly.
1959 ad for the Electrowriter by the Comptometer Corporation.
Brunsviga Nova II mechanical calculator with a pinwheel mechanism.
Sicher und schnell errechnet LZ129 Hindenburg seinen kurs auf Brunsviga Rechenmaschinen
Page from the instruction leaflet for the Comptometer dictation machine. It has a list of 10 commandments for good dictation: 1. I will dictate clearly and distinctly and spell out unusual names and places. 2. I will talk to my secretary through the unit, not to the machine. 3. In an unusually noisy room I will make an extra effort to speak more distinctly into the microphone. 4. When I pause during dictation I will remember to release the microphone switch so that my secretary will be able to judge the length of the letter by looking at the recording log. 5. I will eliminate guesswork for my secretary by dictating punctuation and paragraphs. If there are any notations, isolated P.S.'s, etc., I will make note of them on the recording log which I will use to identify each letter. 7. When an error or changes occur I will take full advantage of this unit's Erase-O-Matic belt and turn over Error-Free dictation to mmy secretary. 8. I will make my letters concise and conversational. 9. If cigars, chewing gum, etc. muffle my voice, I will abstain until my dictation is completed. 10. While noticing the blonde file clerk or other interesting distractions, I will try to remember to keep the microphone near my lips while my head rotates.
Another ad for the Comptometer dictation machine. It pictures a close up of a man speaking into a microphone, looking sideways very guiltily as if he is about to be caught by lieutenant Columbo.
Advert from March 1956 for the Comptometer Commander, a dictation machine made by Felt & Tarrant.
“Are machines smarter than me?” On the right is a line drawing if a distraught man cowering inside a box. It is a 1949 ad for the Comptometer mechanical calculator.
Some of the controls and a counter used in division.
A large mechanical calculator, the MADAS model IX T, from the 1920s.
The ZX81/80 Print ‘N’ Plotter. As you can see, I was into maps
The ZX81/80 Print ‘N’ Plotter Film, for tracing over pictures and converting them to pixel images on the Sinclair ZX81.
Excerpt from the 1989 catalog "Find it! : a resource guide to hands-on math" describing the Pascal-type Calculator.
A toy calculator, made from yellow plastic, with a rotary dial for entering numbers, a two-digit accumulator register on the left, and a counter register on the right.
Not a real Comptometer. How many errors can you spot?
The Facit Wizard figurine in some packing paper next to its original box.
Cover of the Facit NTK manual, showing the mechanical calculator with the Facit Wizard standing on top of it.
Facit Wizard figurine, facing left with his arm outstretched.
A Dialamatic adder with 6 dials and a stylus.
Six Contex B adding machines. The front two are for British currency (pounds, shillings, pence), the middle two are for ordinary decimal additions, the back left one is British currency with farthings (quarter pence), the back right one is decimal but with a halves column.
Light switch with the label above it saying “No function”
Two similar Brunsviga pinwheel calculators - one an older black Nova II, the other a later 13RK.
A National cash register on the shop counter in an antiques store. It has a lovely wood grain finish
A gorgeous Schäffer & Budenberg revolution counter in a lined box.
DVD cover for Deathwatch (2002), a creepy horror movie set in WW1.
A wall switch with the sign "No function".
Tiling using a single pentagonal tile shape (and its mirror image). The blue and yellow pentagons have 5 neighbouring tiles, while the red ones have an astonishing 8 neighbours.
A tiling made of squares, each subdivided into five parallel rectangles. The orientation of these square subdivisions alternate horizontal and vertical. The red rectangle tiles (the outer rectangles of each square) have 8 neighbouring tiles, though all the others have just 4.
A barred grass snake sitting on a lily pad in the pond of our back garden.
A serial number struck into the back plate of an old mechanical calculator. It says 1462, but the 4 is turned 90 degrees, and the 2 was first struck upside down and then only partially struck the right way up.
A wood-cased Comptometer, a mechanical calculator from about 1902.
South Park's A.W.E.S.O.M.-O robot, which is Eric inside some boxes.
"Robot box" that Marion had to wear while he tried to find a hidden object.
Preliminary Studies of a Vaudeville Telepathist, by the University of London Council for Psychical Investigation. Published in 1937.
Near solution to the 3x44 edge-matching puzzle.
Light switch, with a label above it with the text “No function”.
Morning on a lake in Norway, a little North of Rjukan, taken on a holiday in September 2023.
Photo of a tiling pattern used in a partitioning inside the Blue Mosque in Istanbul.
Ad from 1938 for The Radium Spinthariscope, a toy version of a scientific instrument that makes visible the radioactive decay of radium atoms. "Witness The Destruction Of Thousands Of Worlds" It cost just one dollar.
Photo from an Italian manual for the Comptometer calculator, from around 1916. It depicts a man at a desk entering a number in the Comptometer with his right hand, while his left hand is holding a spot in a large ledger book.
Max of this partial solar eclipse
Partial solar eclipse, shown using pinhole in a sheet of paper
Graphics from 3D Monster Maze for the ZX81
Old Philips Bi-Ampli radio, with a Sony transistor radio on top.
Part of the exhibition "400 years of mechanical calculators". This shows about one third of the displays.
Freehand pen drawing of a square, where both the top and right sides have an equilateral stuck to them, forming a non-convex equilateral hexagon shaped a bit like a shield.