This is a Dennert & Pape, made before 1936. From then on, D&P used ARISTO as their trade mark. They made about 150 different models 1872-1935. If it is a 4",
Reply to Charlie Oxford --- re Post 1446D slide rule The Post 1446D was labeled for Post by Lawrence Engineering during WWII. It is a Lawrence 250-BT and is
Hi Bob, I love a challenge! It's a stretch, but.... How about calculating ground speed (magnitude) given air speed and wind speed as vectors (magnitude &
Hi, Bob, if you add a TI scale, then you will find them useful for doing complex number calculations using proportion. The DI scale has superseded this. There