nzeldes 
This is Jaen-Antoine Lafay’s Hélice a Calcul, a rather unusual logarithmic slide rule. But Lafay himself, its inventor, was just as unusual, not to say quirky… a fascinating lone innovator waging war on an indifferent world. To illustrate, here is a section from Lafay’s marketing brochure: Oh, routine! What wrong do you not do, firstly … Read more
In the days before GPS, Google Maps and Waze, people used maps; and to figure how long it would take to get from A to B on a map, you could make excellent use of a Marsch-Zirkel, or march compasses… like the lovely device described in this new article on my History of Computing exhibition. … Read more
An important element of everyday product design that is all too often ignored is the footprint of an object. I mean, look at these two electric kettles, which are very common kitchen appliances. They serve the exact same purpose; they use the exact same technology; they have the same water capacity. But there’s a big … Read more
Kerosene heaters are smelly, require much maintenance, and are dangerous if used carelessly; on the other hand they create a lot of heat, are independent of utility feeds, and for us older folks they actually have a nostalgia evoked by the conditioned association of the kerosene smell and the pleasant warmth of years past. Be … Read more
The Baines slide rule is one of the most unusual ones in my collection, because of the metal contraption on its back that moves all its parts in unison. Here it is: This slide rule was designed by a British civil engineer from the Punjab; it is used to calculate water flows and pressure drops … Read more
Clearly marking tool and instrument controls is always a good idea, but it becomes vital where safety is at stake. And if there is one control where safety is definitely at stake, it is the safety catch! Like this one, on a rechargeable jig saw from Taiwan: See the switch clearly marked “Safety Lock”? Very … Read more
These days the preference for shoddy, cheap, use-and-discard products is all over the place. Here is an example: This sorry street sign in Jerusalem has taken on a very “artistic” look – because it is made from a blue layer of stick-on plastic sheet over a metal plate. Over time the plastic started to shrink … Read more
Some of the most fascinating items in my History of Computing collection are the one-of-a-kind, undocumented ones. The latest such addition to the collection is a calculator hidden in a book-like case, that has no mention anywhere that I could find. This is Charles Cornell’s F.24 aerial photography planning calculator, and you can read all … Read more
Was on a United flight enjoying my coffee (such as it was), when I noticed the text on the paper cup. Nice cup: Makes them feel very ecological, no doubt… someone in Marketing must’ve though it a good point to brag about. Except that it’s completely meaningless, of course. This statement remains true even if … Read more
Say “Alice in wonderland”, and the image that comes to mind (well, at least in the generations that used to read books) is a little girl in a tidy Victorian knee-length puffed sleeve dress with a pinafore, and long blond hair – the girl in the image at right. This comes from the famous illustrations … Read more
