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
I was at this coffee shop and saw the two machinettas. Of course I didn’t buy one – as coffee lovers, we have all the machinettas we need at home – but I did notice how the pair represents two different solutions to a small but important design bug that the classic machinetta had subjected … Read more
This new article on my Possibly Interesting site is strictly for radio amateurs and other geeks: a photo-essay depicting circuit and construction details of the SSB transmitter I’d built a long time ago. What makes it interesting (other than the nostalgia of vacuum tubes, that is) is the prevalence of improvised, scavenged and military surplus … 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
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
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
This Barometer was made in Florence some 100 years ago, and served my late grandfather, first in Italy, then in Israel; it ended up on my wall, a family heirloom to delight the heart of any engineer. It is a large (23 cm across) Aneroid Barometer, an instrument to measure atmospheric pressure by means of … Read more
I was sitting in the lobby of the Shaare Zedek hospital in Jerusalem, and I noticed on the chair next to me a small booklet someone had discarded there. An idle look turned to admiration as I examined it and realized what it was. The cover reads “EEG test – the Institute for Neurological Diagnosis“, … Read more
New on my Possibly Interesting web site: Cloning a Vibroplex bug, where I describe the venerable Vibroplex semi-automatic telegraph key – and the improvised clone I made as a young radio amateur. Enjoy!
