Harvard Project Physics Circular Slide Rule

The slide rule is a device to assist in multiplication, division and other mathematical operations. Invented in the 1600s, it became popular in American science and engineering in the 1890s. By the 1930s, slide rule use was taught in high schools.

From 1962 until 1972, Harvard University faculty cooperated with others in developing a humanistically oriented high school physics course that might attract more students to the subject. Staff developed not only textbooks, handbooks, transparencies and film loops but this extremely simple and inexpensive plastic slide rule.

The instrument has two circular logarithmic scales for multiplication and division (most elementary slide rules also had scales for taking squares and square roots). There also are linear scales of inches and centimeters.

A stylized bubble chamber image, the logo of Project Physics, appears over the rule. The slide rule was designed so that "Harvard Project Physics" showed just over the shirt pocket of a boy carrying it. This design may reflect the fact that there were no female undergraduates at Harvard College at the time. Not long after this slide rule was made, inexpensive pocket calculators displaced the slide rule.

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