After looking for a long time, I finally found this #Sliderule, which belonged to my late father. Some of you will know that these #devices were used, before the advent of digital #Calculators, to perform #arithmetic operations such as #multiplication and #division to about three significant figures, by #scientists and #engineers. Not only is it of sentimental and historic value, I think it's a testament to the skill of those who have made high-precision instruments through the ages. To this day, #CircularSliderules are used by trainee #Pilots to do #calculations and to convert units, etc. To me they're a thing of beauty as well as utility.
