|
|
This 5 inch pocket rule is made of mahogany wood with plastic coated paper and with 6 scales: A, B, C and D, Log-Log and Reciprocal. The cursor is made of plastic with a single hairline. This type of cursor was used on early Unique models. On the backside, a table lists values for trigonometrical ratios: sine, cos, tan and cot for 1 – 90 degrees. Some yellowing has occurred, otherwise in good condition.The ‘UNIQUE’ Company was established in England in 1920. |
|
