Today medical thermometers are electronic contraptions that come in various forms and are easy to use and easy to break – as disposable as most everything seems to be of late. When I was a kid medical thermometers were glass tubes with a thin line of mercury running up on a scale inside it, terminating … Read more
Museum visits never lack for cool stuff! So here is a sighting from a recent visit to the Israel Museum in Jerusalem. These are anthropomorphic sarcophagi (ossuaries) from a chalcolithic burial cave found near Peki’in in the Galilee. Made of painted clay, they are dated to 5,500-6,500 years ago. Clearly functional as containers for bones, … Read more
We’ve all enjoyed playing board games – Timeless ones like Chess and Checkers, and more modern ones like Monopoly and Risk. So I was in the Israel Museum the other day and saw the game in the photo above. This is Senet, a two player game from ancient Egypt. This particular item is from 15th-13th … Read more
The humble clothespin is a ubiquitous item that has been with us for generations; and it is simple enough that you’d think it’s reached the point if utmost reliability. And yet, it seems that it is in fact very unreliable: clothespins break, they fall apart, they need constant replenishing… but I seemed to remember that … Read more
The photographic camera is one of the great inventions of the 19th century, and is quite a simple idea: take a light sensitive surface, put a lens in front of it, add the ability to control exposure time and aperture, and you’re all set. And for more than a century, that’s what cameras were all … Read more
The Tavernier-Gravet company was France’s premier scientific instrument maker at the end of the 19th century, and it stayed abreast of the latest developments in slide rule design and production when it entered the 20th century. In this this new article on my History-of–Computing site I illustrate some of their problems and solutions as they … Read more
When my kids were at school they were taught addition with colored wooden rods. Well, a century earlier two innovative Frenchmen – Henri Genaille and Edouard Lucas – invented a system that does rapid multiplication and division using much more sophisticated rods, and I have in my collection a box of these ingenious calculation aids. … Read more
Monsieur C.-F. Martin was a retired naval clerk, and evidently he had developed a great love for painstaking calculation. Just see this 100×100 multiplication table and units conversion tables he published at the beginning of the 19th century, to help his countrymen deal with the switch from the old Empire weights and measures to the … Read more
A few years ago I sighted on eBay a set of three German circular slide rules of the Controller brand. There was a big one, 20 cm in diameter; a midsized one 11 cm across; and a small one at 7.5 cm. They all looked pretty much the same except for their sizes, and this … Read more
The circular slide rule developed around 1920 by Jules Arnault and Louis Paineau comes in a wooden frame, to give it durability and ease of use; but it is so pretty you can – and I did – hang it on your wall! Aside from being pretty, this is an ingeniously designed and very well-made … Read more
