Very Early Large Transit – One of Two Known 1854 Gurley Engineer’s Transits

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Gurley became the largest surveying manufacturer in the country because it marketed and sold high quality instruments at a reasonable price on a nationwide basis. The marketing campaign was especially brilliant – Gurley issued annual Instrument Manuals (Catalogues) reflecting their entire product line starting in 1855.

This 1854 Engineer’s Transit was a very important evolutionary step in Gurley’s rise to dominance.

W. & L.E. Gurley started business in 1852 after William and Lewis Gurley acquired all of the interests in the Phelps & Gurley firm. Phelps & Gurley produced a full line of surveying equipment, including compasses and transits. The transits were very distinctive, as most of them featured curvilinear telescope supports (making them very collectible nowadays). While Phelps & Gurley started making transits with “A” frame telescope supports before the sale to the Gurley brothers, very few examples of “A” frame Phelps & Gurley transits are known.

W. & L.E. Gurley continued to evolve the Phelps & Gurley transit product line after starting business in 1852. There are very few known Gurley transits from the 1852 thru 1854 period. The few transit pictures that I have seen (from Aregood’s book on dating Gurley transits) show either smaller transits with squarish horizontal plates or transits with circular horizontal plates with overly long telescopes (given the poor nature of the glass). Gurley apparently perfected the design of its transits in 1854 (likely after Gurley had secured better glass from France) – Gurley would use the basic 1854 design well into the 20th century.

This transit has features only used in 1854. Compare the locking plate mechanism and tangent screw placement (under the horizontal plate) on this 1854 transit, for example, to the 1855 Engineer’s Transit in Gurley's 1855 Manual (on top of the horizontal plate).

According to a label on the original oak box, Gurley serviced this transit in 1875. I believe Gurley either refurbished and updated the original telescope or replaced the original telescope at that time. The telescope works great, however, with the crosshairs in place as well as the stadia lines.

Interestingly, this compass features spring mechanisms on two tangent screws. The spring on the tangent screw under the horizontal plate looks like it could have been added by anybody. The unique spring mechanism on the telescope tangent screw looks very professionally done, and I wouldn’t be surprised if Gurley added that spring when it serviced the transit in 1875.

The oak box is in very good condition, and has some interesting features as well, including its original label.

The transit also comes with its believed to be original tripod.

I know the history of this instrument going back roughly 100 years based on a narrative from the person I purchased the transit from. I will share that narrative with those who express an interest in the instrument. I cannot find any reference on the internet however to the circa 1900 surveyor who apparently used the transit.

I just added some pics of the transit on its tripod. When you look at the transit from eye level, you can see that the transit fell over at some point. The plate looks a little bent. Can't really tell whey you are looking at the plate from different angles however - just eye level.

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