Offered here is a VERY hard to find Circa 1853 Gurley Curvilinear Transit. The Curvilinear term comes from the curved shape of the standards.

This transit is essentially a Gurley vernier compass but with a telescope instead of sight vanes Over the years Gurley called this transit different things - the VTC, the Vernier Transit and the Transit Compass. I like VTC.

Gurley only made the Curvilinear Transit (or VTC) from 1852 to 1854 or so. Gurley abandoned the curved legs by 1855. Gurley's 1855 Catalogue (the First Edition) does not show any transits with curved standards.

How do you tell a VTC from a Transit? The VTC lacks a horizontal circle. The early Gurley manuals describe how much better a VTC is than a comparable vernier compass with sight vanes - see the pics at the bottom of this webpage for all the reasons why Gurley says a VTC is better.

This Gurley Curvilinear Transit is in very nice condition and would look fantastic on display. To really appreciate this Gurley Curvilinear Transit, please take a look at the 360 Degree View linked below for this instrument.

Based on the design features of this VTC and the label inside the box, I believe the VTC was made sometime in 1874 or 1875, give or take a couple of years. I used Brian Aregood's book on dating Gurley transits to date the instrument. Great book.

This Gurley Curvilinear Transit does not have a box or staff adapter. The pics show everything I have. The needle is 5 1/2 inches long.

The telescope thumb screw is hard to work. Almost frozen. Optic still seem OK however

Telescope is 11 1/2 inches when closed. Vernier mechanism is worn and probably needs cleaning and oiling.

The transit is approximately 10 inches high. Both levels have liquid.

The standard on the east side is adjustable

Staff adapter hold-down thumbscrew mechanism is pretty unuusal for a Gurley instrument.

The last pic below is from Aregood's Gurley book - it shows a nearly identical Gurley Curvilinear Transit.

I have a good deal of information about Gurley, including some production information, posted on my Gurley Maker Webpage.

Gurley Curvilinear Transits rarely come up for sale. My records reflect that a wonderful Phelps Gurley Curvilinear Transit sold on eBay for $6300 in 2001 and a Gurley Curvilinear Transit sold at Skinners in 2019 for $3075.