Collection of pages from K&E catalogs for the 4071-3 Family of Slide Rules
The 4070-3 and 4071-3 family of slide rules are duplex type slide rules. The 4070-3 and 4071-3 are identical except that their Trig scales have different graduations. The Trig scales on the 4070-3 are divided in degrees and minutes where as the 4071-3 is divided in decimal degrees. These slide rules were only offered in 10" versions. A 5" plastic slide rule, the 4168-1, was offered in the mid 1950s that was very similar with a sub-set of the scales but it will not be included in this discussion.
For a short period on time in the early 1950s when the Doric series was released. The 9071-3 was made on a plastic frame. To this date there is no documentation that it existed, however there is an example in this collection. The 9071-3 is identical to the 4071-3 of that time except for the plastic frame.
These slide rules were constructed on a mahogany frame with celluloid laminated to the surface. The markings are engine divided. The scales on the 4070-3 and 4071-3 are as follows:
- DF = CF CIF CI C = D L ------- K A = B T ST S = D DI (1939 - 1955)
- DF = CF CIF CI C = D L ------- K A = B T SRT S = D DI (4071-3 only 1956 - )
These slide rules were an evolution of the 4088 family of slide rules. They are constructed on the same frame and the scales are similar. For a comparison, the scales of the 4088s are shown:
- DF = CF CIF C = D ------------ K A = B S T CI = D L
The following models are part of the 4071-3 family:
- 4070-3 --- 10" Polyphase Duplex Trig
- 4071-3 --- 10" Polyphase Duplex Decitrig
- 68 1497 -- 10" Polyphase Duplex Decitrig
- 68 1502 -- 10" Polyphase Duplex Decitrig
- 68 1524 -- 10" Polyphase Duplex Trig
- 68 1529 -- 10" Polyphase Duplex Trig
- 9071-3 --- 10" Polyphase Duplex Decitrig Plastic
The 4070-3 and 4071-3 first appeared in the 1939 catalog. The 4071-3 family last appeared in the 1967 catalog. The following is a brief history of the 4071-3 family of slide rules as is told in the K&E catalogs that are available at this time. Exact timing is not possible because of the time between catalogs.
- 1939 - The 4070-3 and 4071-3 were introduced.
- 1949 - The Doric 9071-3 was mentioned in the spare parts section for cursors of the 1949 catalog. This is the only reference found in any printed material available.
- 1955b - The ST scale on the 4071-3 was replaced with the SRT scale. Note: The illustration on page 276 shows the ST scale while the scale description on the next page describes the SRT scale. The top and bottom edges of the rule have inlaid laminate instead of solid laminate. There is no printing on the edges.
- 1962 - The model numbers were converted to the 68 xxxx series of numbers.
- 1967 - Only the 4071-3 (68 1497 and 68 1502) are shown in this catalog
- 1972 - Does not appear in this catalog.
Links to catalog pages for the 4071-3 family of slide rules:
Link to scans of 4071-3 Family of Slide Rules