Slide Rule Collection
Slide Rule Collection

The slide rule is a mechanical analog computer.

The rulers each have a logarithmic scale(the spacing between the lines on the scale become smaller as the value increases), it is possible to align them to calculate the product of two numbers.

The Slide Rule

I am using a Hemmi Bamboo with A, B, CI, C, D, K, S & T.


2.2 × 3.5
3.2 × 4.6

Trying to slide the cursor toward 4.6 will reach the end of the scale, we must use the inverted CI scale.


3.2 / 4.6






Ax2square1 to 100On body. Two log cycles at half the scale of C/D.
Bx2square1 to 100On slider. Two log cycles at half the scale of C/D.
CI1/xreciprocal C1/0.1 to 1/1.0On slider. C scale in reverse direction.
Cxfundamental scale1 to 10On slider.
Dxfundamental scale1 to 10On body.
Kx3cube1 to 1000Three cycles at one third the scale of D.
Ssin(x)sinsin(5.74°) to sin(90°)On backface, above.
Ttan(x)tangenttan(45°) to tan(84.3°)On backface, below.
Hemmi Bamboo Backface S25
Hemmi Bamboo Backface S25
Hemmi Bamboo Frontface B42
Hemmi Bamboo Frontface B42

Incoming: paper computing 2022