Pickett Model 4 Deci Log Log Vector Hyperbolic

The Model 4 Deci Log Log Vector Hyperbolic slide rule was produced in the United States from 1947 until 1959, when was replaced by the Model N-4. Fabricated with magnesium coated with very thin celluloid, cursor made with transparent plastic screwed to aluminum ends, and hold with steel end posts. Scales were photographically printed on the celluloid.

This was the most powerful rule Pickett produced during those years, with 30 scales was a great tool for Scientists and Engineers. As the model 3, it was designed with 8 Log-Log scales (an 80 inches long scale split in 8 parts), 3 cube - cubic root scales (a 30 inches long scale split in 3 parts), 2 square- square root scales (a 20 inches long sclae spolit in 2 parts), and 3 trigonometric scales. But Model 4 has 3 additional scales for trigonometric hyperbolic functions.

The specific scales on the Model 4 are: 1/N1, 1/N2, 1/N3, 1/N4, D [ CF, Th, Sh, Sh, CI, C ] D, N1, N2, N3, N4 on the front face, and 3√ #1, 3√ #2, 3√ #3, DF [ CF, T, ST, S, CI, C ] D, DI, √ #1, √ #2 on the back face.

In 1949 the Model 4 had a re-design in the Log-Log scales, cube-cube root, and square - square root scales. Log-log scales were paired by reciprocals (i.e. N1 with 1/N1, N2 with 1/N2, etc.) and drawn on the same line, one scale pointing up and the other pointing down. Same was done with the root-scales. This made the Model 4 less scales cluttered. There were some other minor changes during the next years like the different labels of the Log-Log scales.

The model in this collection is one of those produced during the years 1947-1948:

Problems that can be solved with a precision of two-three decimals with the Model 4 rule:

SRPractice-3.pdf

Here is a scan done by the International Slide Rule Museum of the User Manual for the Model 4 rule:

Pickett_Model_4_Vector_Hyperbolic_Instructions_ScanByMarionMoon.pdf

Click on the next links to see professional panoramic pictures of the Model 4:

1947 (All scales separated)

https://www.sliderulemuseum.com/Pickett/S196_Pickett_Model_4.jpg

1949 (Log -Log scales interchanged places. Log-Log, Cubic and Square root scales are grouped)

https://www.sliderulemuseum.com/Pickett/S544_Pickett_Model4_Mag_VectorHyperbolicLogLog1949.jpg

References.