Circa 1860 Gurley Vernier Compass

Nice Gurley Vernier Compass Circa 1860

This is a very nice and early Gurley Vernier Compass. My records reflect that the Vernier Compass offered here for sale was acquired by its prior owner for $1645 at an eBay auction in 2004.

The 2004 auction involving this compass described the compass as a Circa 1870s compass. That dating was based on the fact that Gurley started machine engraving instruments in the mid-1870s. The eBay seller likely estimated the date of the compass as circa 1870s because the compass is hand-engraved, thereby pre-dating Gurley's adoption of machine engraving in the 1870s.

I dated this compass using Brian Aregood's definitive Gurley dating guide - "The Complete Guide to Early W.L. & E. Gurley Transits". While the book focuses primarily on Gurley transits, many of the dating techniques Brian developed apply equally to other Gurley instruments as well.

Brian's research shows that Gurley used different divining engines on the compass faces over the years. Since the earliest machines were fairly simple, Gurley added guide lines around the compass face to help keep the machine cuts of consistent length. According to Brian, Gurley stopped using the guide lines around 1865. The relevant page from Brian's book:

The Vernier Compass offered here has the guide lines which, according to Brian's Aregood definitive book on Gurley dating, put this instrument as 1865 or before. Since Gurley sold very few surveying instruments during the Civil Was years, I estimated the date for the Vernier Compass as circa 1860. But it could be as late as 1865 or so.

As described in Gurley's 1862 Instrument Manual, this is the large version of Gurley's Vernier Compass. 15.5 inches long, with a 6 inch needle (I measure closer to 5.75, but Gurley says 6). The instrument offered here has its original box and vanes, a staff or tripod adapter, a plumb bob and a small tool. The believed to be original tripod is included as well. See pics below for everything that is included in the sale. One of the two levels still holds liquid. The other level has glass that apparently no longer holds liquid.

This is a very nice early Gurley Verier Compass.

SOLD - Email Russ