"sliding Gunter" slide rule
Date: circa 1750
Inventory Number: DW0961
Classification: Slide Rule
Dimensions:0.7 x 62.5 x 5 cm (1/4 x 24 5/8 x 1 15/16 in.)
DescriptionTwo-foot-long boxwood rule with three slides of different widths. The top and bottom slides are fixed to rectangular brass plates on each side of each end of the rule. The center slide moves to left and right.
The face of the slide rule is printed with fourteen scales. Near the top edge of the top, fixed slide is a "Cube" or "C" scale composed of three logarithmic scales (values 1 to 10) placed side by side. Along the center of the same (top) slide is a logarithmic "Root" or "R" scale carrying values from 1 to 10. Along the bottom edge of the top slide is printed is a "Numb." or "N" scale composed of two logarithmic scales (values 1 to 10) placed side by side. Certain points along the "N" scale are marked with dots. These are labeled (from left to right): "s1", "se9", "D", "B", and "C".
Printed along the top edge of the center, moveable slide is a "Numb." scale identical to the scale on the bottom edge of the top slide. Below this is a "C" scale composed of a logarithmic scale that wraps around from 4 to 10 to 4(0). Certain points along the "C" scale are marked with dots. These are labeled (from left to right): "ST", "RT", "W", "A", and "W".
Along the top edge of the bottom, fixed slide is a "Numb." scale composed of two logarithmic scales (values 1 to 10) placed side by side. Printed second from the top on the bottom slide is a "Root" scale identical to the "Root" scale on the top slide. Third from the top is a "Square" or "S" scale identical to the "Numb." scale on the same slide. Below this are scales for, from right to left: "M·Log~", with values descending from 60 to 0; "Ch", with values descending from 90 to 0; and "M", with values descending from 73 to 0. Printed near the bottom edge of the bottom slide are, from left to right: an "L" scale, with values descending from 90 to -10; a "Rum" scale, with values descending from 8 to 0; and an "E·P" scale, with values descending from 100 to 0.
The back of the rule is printed with thirteen scales. Printed near the top of the top, fixed slide are scales for, from right to left: "Sec~", with values descending from 74 to 0; "Sin", with values descending from 90 to 0; and "S·R", carrying values from 1 to 8. Second from the top along the same (top) slide are, on the left, a "Tan" scale with values descending from 75 to to 0; and, on the right, a "T·R" scale, with values ranging from1 to 4. Printed along the center of the slide is an "S" scale carrying values from 1 to 90. Below this is an "N" scale composed of two logarithmic scales (1 to 10) printed side by side. Printed along the bottom edge of the top slide is a "T" scale carrying values from 1 to 45. Beside each of the marks for 10, 20, 30, and 40 is an additional, smaller number (8, 4, 9, and 5, from left to right).
An identical "T" scale is printed along the top edge of the center, moveable slide. Along the bottom edge of the center slide is an "S" scale identical to that on the top, fixed slide.
Two additional "S" scales are printed along the top and center of the bottom, fixed slide. Printed near the bottom of the same slide is a V·S scale with values descending from 160 to 0.
A scale in inches, graduated into tenths, is printed along the bottom edge of the rule.