World War 2 defence industry Trig-Easy trigonometry charts

The Trig-Easy trigonometry aids were produced by E H Needham of Culver City California during World War 2. The US defence industries expanded greatly during the war, particularly in California,  and must have needed to train many new machinists etc. I think Needham produced the Trig-Easy charts for this market.

I think my set of Trig-Easy charts is complete. It consists of the following

1.  A case showing the charts were intended for engineers, machinists and others involved in mechanical engineering.

2.  A plane trigonometry chart and an eight page folding pamphlet.

3.  A compound angles chart and 144 page instruction book with illustrations, many worked examples and tables. The book was copyrighted in 1943 and revised and enlarged in 1945. This chart is marked as being sold by Eugene Dietzgen.

4.  A spherical trigonometry chart and 16 page pamphlet marked ‘This pamphlet is written with the view of helping defence workers who have become rusty with trig problems….’

Charts side one

Charts side 2

Case and compound angles book

Compound angles book

Spherical trigonometry booklet

Plane trigonometry pamphlet

Advertisement from February 1949 issue of Popular Science

1 Comment

Filed under Calculators, History

One response to “World War 2 defence industry Trig-Easy trigonometry charts

  1. Peter Mackinlay

    Thanks for that. I just bought a September 1944 Popular Science magazine (Black Widow fighter plane on the cover) at a Sunday Market today and found an advert for Trig-easy. Your posting helps explain what it was like.
    Peter Mackinlay, Geelong Australia ( a slide rule lover)

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