## BINARY CIRCULAR SLIDE RULE (Dec, 1954)

CALCULATIONS of all kinds can be easily solved on the BINARY CIRCULAR SLIDE RULEThis rule will quickly solve the simplest as well as the more difficult problems involving calculations in Arithmetic, Algebra and Trigonometry. Any number of factors can be handled in long and difficult calculations. The C scale of the Binary is 25 inches long with graduations 25% further apart than those of a 20-inch slide rule. The CI, A, K, & Log scales are divided as closely as a 20-inch slide rule. Log-Log scale extends from 1.0015 to 1,000,000. Gives Trig, functions from 0 to 90 degrees on back. Engine-divided scales yellow and black on white coated aluminum. Permanently accurate. Di a. 8-1/2″. Price $8.50 in case, with instructions. Approved at leading Univ. Used by many large firms in the U.S. Midget size 4″ dia. with case $3.

NEWLY IMPROVED

ATLAS SLIDE RULEThe Atlas Slide Rule will quickly solve problems in Multiplication, Division, and Proportion and give results with a maximum error of less than 1 in 36.000. The Atlas has two C scales. One is 25″ long and the second one is a spiral of 25 coils. This is equivalent to a straight rule 60 ft. long and gives answers to 5 figures.

Chemists. Physicists and Engineers have found this rule invaluable for its great accuracy. Dia. 8-1/2″. Easily portable. White coated aluminum with legible black and yellow scales. Price $11.00 in case with instructions.

Combination Atlas-Binary Slide Rule

Has Atlas front scales on one side with 2 indicators, Binary front scales on reverse side with 2 indicators. No Trig. scales. Made of metal, permanently accurate. Price $15.00 in case with instructions.

Descriptive circulars free. Satisfaction guaranteed.

GILSON SLIDE RULE CO.

Box 993 SA, Stuart, Fla. Slide Rule Makers since 1915