Trammell HudsonSlide rule fans: have you ever seen one with two cursors and a second sliding rule? This odd sliderule illustration was on the cover of Astounding Science Fiction, May 1951 https://archive.org/details/Astounding_v47n03_1951-05_Sam_Hall/mode/2up
mcc
CalvinBall@th Xzibit's sliderule 
Marcus Müller@th I've seen one with one cursor and an inner slide like yours. I don't remember what the special purpose was, or whether it was just missing the second cursor
🏳️⚧️ Chloé: IA Vegan@th
I never saw that kind of second slider indicator.
I never saw that kind of second slider indicator.
cynicalsecurity 
@th one of my father's sliding rules is like this, I have it somewhere...
The Doctor@th Only in books about slide rules. I've never actually seen or used one.
Lee Holmes 
@th It kinda looks like that rule is for unit conversions? So maybe to support a->b with regular C/D scales and multiple b->c conversions where you don't want to lose your original calculations?
@th Oh, that magazine is sci-fi. Perhaps it's just invented to look fancier and more complicated.
mb21
slash@th An astrophysicist I knew had an old one with both the double slides and double cursors.
But otherwise I´ve only ever seen them in books or magazines.
Gina W@th I used to have a few similar ones for calculating feeds and speeds rather than general math. They were intriguing but in practice I mostly used a computer.
@ginabythebay were they linear or circular rules? I've seen round ones with three wheels for specialized computation like IBU.
