TRANSIT COLLECTION

 

 

TR 1, Plain Theodolite w/Geared Vertical Limb, George Adams, maker, London, c. 1790.

George Adams, Jr. (1750-1795) was a leading maker of mathematical instruments. He was instrument-maker to George III in succession to the elder George Adams (1704-1773), and optician to the Prince of Wales. He wrote numerous books of a scientific nature.

The instrument has a 7º" horizontal circle, a partial 7º" vertical circle, and a 4" needle. The vertical circle is divided from -41° to +105°. The telescope is 13.2" long. The instrument is missing some parts. These are one plate spirit level, the internal-horizontal rack-and-pinion knob, and the needle-arrestor arm.  It is inscribed "G. Adams, London." The upper horizontal limb under the objective end of the telescope has divisions, noted by the inscribing "Tang. to 100 of Radius." The leveling base has a spring-opposed tangent screw, which is apparently a retrofit since there is no evidence the spring-opposed feature was used in the 18th century. The instrument is depicted on Plate 16 of George Adams' Geometrical and Graphical Essays, 2nd ed., 1797. It is complete with case and tripod.  Here is a 360 degree view of the Adams Theodolite.

 

TR 2, 30" Surveyor's Transit, John Roach, maker, San Francisco, CA, c. 1872.

This is a fine example of this noted pioneer California maker. It has a 7" horizontal circle to 30 seconds, and a 5" full vertical circle to 1 minute, and a 4 3/4" compass needle. Pencil markings inside the wood case read "P J Fitzgerald, Junior Class 02 St Marys College, Oct 2 01. There are 2 Sala cards inside the case, and one from the Seattle Optical Co. The instrument is complete with tripod. The compass dial has fancy original swirl-pattern polishing.  Click here for a picture of the fancy dial.

 

TR 3, Single Vernier Surveyor's Transit, Edmund Draper, maker, Philadelphia, PA, Serial No. 174, c. 1860.

This instrument has a 6" horizontal circle, a 5" vertical circle, a 4.6" needle, and a 10.6" long telescope. There is no clamp mechanism to the telescope. It comes with the original tripod but has no case.   The compass box is inscribed "Edmund Draper, Philadelphia, 174."   Here is a 360 degree view of the Draper Transit.
 

TR 4, Single Vernier Surveyor's Transit, W. & L.E. Gurley Co., maker, Troy, NY, c. 1870.

This instrument has undocumented provenance to 19th century surveyors Hatch & Eaton in Nevada. It was reportedly used by them in 1871 on public land surveys and for the early layout of the NCO Railroad. Hatch was president of the railroad in 1870.

The compass dial is inscribed "W. & L.E. Gurley, Troy, N.Y., Chas. G. Ewing, Agent, San Francisco, Cal." It has a 6.6" horizontal circle, a 3.6" vertical circle, a 5" magnetic needle, and an 11" telescope. The leveling base is detachable from the upper portion of the instrument. Charles Ewing was the S.F. agent for Gurley during about 1869-1873.

This instrument is pictured on page 31 in Chaining the Land. 

 

TR 5, 3" Traveller's Transit Theodolite, L. Casella, maker, London, Serial No. 3712, c. 1875.

This tiny instrument comes with several accessories including a separate high-power eyepiece. It is brass construction finished in black and brass finish. It has a wood case plus a cloth case for the wood. It has a 2.75" horizontal circle, a 2.5" vertical circle, a 1.5" needle, and a 6" telescope with the low-power eyepiece. The compass box is inscribed "L. Casella, Maker to the Admiralty & Ordnance, London, 3712." The graduations to the horizontal circle are external. The tangent screws are not spring-opposed. It is modified from Casella's first model of the Traveler's theodolite.

 

TR 6, Light Mountain and Mining Transit, W. & L.E. Gurley Co., maker, Troy, NY, c. 1885.

This transit has a 6" horizontal circle and a 4" needle. It is missing the vertical circle it once had. The vertical slow-motion screw is spring-opposed and is possibly a retrofit. The horizontal slow-motion screws are not spring-opposed. The instrument has a black finish. Inside the transit is scratched "WEH Seattle 8/8/92."
 

 

TR 9, Light Mountain Transit w/Burt Solar Attachment, W. & L.E. Gurley Co., maker, Troy, NY, c. 1899.

This instrument has a 5 3/4" horizontal circle and a 4" needle. It has a partial vertical circle. Inside the instrument is scratched "Wood 4-19-07 Wenzel, Seattle 5/6/1908." This instrument is complete with a leather covered mahogany case and extension-leg tripod.  Here is a 360 degree view of the Gurley Solar Transit.
 

 

TR 10, Mountain Solar Transit, Young & Sons, maker, Philadelphia, PA, Serial No. 8375, c. 1909.

This transit is Catalog No. 10. It is of aluminum and brass construction and is fitted with a Smith Telescopic Solar Attachment. It has a 4½" horizontal circle, a 4" vertical circle, a 3.3" needle, and a 10" main telescope. The telescope on the Smith solar unit is 7" long, and is inscribed "Pat Sep 16, 1902." There is a counterweight on the standard opposite the side with the solar unit. The leveling base is from a 1908 patent. It is complete with case and tripod.  This instrument is pictured in the middle of page 16 in the 1980 illustrated price guide.  Here is a 360 degree view of the Young & Sons Mountain Solar Transit.

 

TR 11, Wet Mining Transit, C.L. Berger & Sons, maker, Boston, MA, Serial No. 7814, Catalog No. 4C, c. 1915.

This instrument has a 4" horizontal circle, a 4" replacement vertical circle, a 2½" magnetic needle, a 7½" main telescope, and a 4½" auxiliary telescope.  It comes with Berger's Improved Prism and Colored Glass attachment to the eyepiece.  This instrument was ordered from the Berger factory on Jan. 20, 1909 by the Salt Lake Blue Print Co., Salt Lake City, UT. It is a Berger 4C Mining Transit.

 

TR 16, Mountain & Mining Solar Transit, A. Lietz Co., San Francisco, c. 1900.

This is a Lietz No. 12 aluminum transit. The top of the telescope is fitted for a Saegmuller-type solar attachment which is now missing. It has a 4" horizontal circle, a 4" vertical circle, and a 2 1/2" compass needle. It is serial number 1221.

 

TR 17, Solar Transit, C.L. Berger & Sons, Boston, SN 15267A, c. 1925.

This transit is brass with a black finish. It is 13 3/4" tall without the solar attachment. The solar unit is Berger's version of the Saegmuller unit and is contained in a separate case. The transit has a 12" telescope and the horizontal circle is 6 1/4" in diameter. The transit is Berger catalog number 1-S.  Here is a 360 degree view of the Berger Solar Transit.

 

TR-19, Surveyor's Transit, Richard Patten & Son, Maryland, c. 1850.

This is a unique design of surveyor's transit and is described in Robert Miller's article in Rittenhouse, Vol. 7, Issue 28, August 1993, titled "The First Surveyor's Transits, 1852-1862." This style has the standards attached to the lower horizontal plate instead of the upper. It was intended for retracing land boundaries rather than for engineering purposes. The transit has a telescope 8 1/2" long, a 4 1/2" long compass needle, and a horizontal circle 6 inches in diameter reading by vernier to one minute of angle. There is one spirit level located just below the horizontal plate, another on one of the standards, and a third affixed underneath the telescope. There is no vertical circle.

The transit has no leveling base but instead sits on a spindle affixed to a tripod. The spindle has its own leveling mechanism with 4 screws. The instrument is detached from the tripod in the same manner as a compass. Inside the case is a label of John Roach, a San Francisco maker of surveying instruments.

Richard Patten is said to have entered into a partnership with his son, George, in the 1830's. They relocated their business to Baltimore where this instrument was made about 1850. George died in 1857 after which Richard continued in business by himself.  Here is a 360 degree view of the Patten Transit.

 

TR 20, Cradle-type Plain Theodolite, J.M. Hyde, Bristol, England, c. 1845.

This is the classic English plain theodolite used in America for angular measurement until the mid 19th century. It was then being replaced by the surveyor's transit although the popular Davies Surveying text continued to include the theodolite until the 1883 edition. This instrument has a 12-inch telescope set in wye supports with a 4 1/2-inch level mounted underneath. There is also an exterior 5 1/2-inch horizontal circle reading by vernier to one minute of arc, a 6-inch diameter vertical half circle reading to one minute, and a 2 1/4-inch compass needle.  The telescope image is inverted as typical of the period.
 

TR 21, Boundary Precision Theodolite, A. Lietz Co., San Francisco, Serial No. 8990, c. 1922.

This large surveying instrument is Lietz's Model No. 5 U.S. It was used on the Doulton Tunnel survey that brought water to Montecito. The tunnel was completed in 1928. The circle diameters are 7 inches horizontal and 5 inches vertical. Both circles have two verniers. They are read to 10 seconds and 30 seconds of arc, respectively, using four individual built-in microscopes. The telescope is 12 inches long with inverting image. A striding level mounts across the standards to assist in final leveling, and extra eyepieces and an additional reticle are included inside the telescope case. An oil-burning lamp illuminates the telescope cross hairs when working under low light conditions. The lamp mounts near the top of the left standard and shines light through the hollow axle into the telescope. Most case accessories appear to be present, including an original hand-held penlight for illuminating the scales. It is complete with original tripod. Because of the large size the instrument comes packed in two wooden cases.

 

TR 22, Solar Transit, Buff & Buff Mfg. Co. Boston, MA, Serial No. 14240, c. 1920.

This former U.S. General Land Office instrument was in use from 1920 to 1964. . It is described as USGLO Model-A Solar Transit, Model of 1914 and was purchased new by the USGLO in 1920. The telescopic solar attachment is a modification of the Smith design. The transit has a 2-inch magnetic needle, a 4 1/2-inch horizontal circle reading to one minute of arc, a 4-inch vertical circle also reading to one minute of arc, a 9-inch main telescope with level underneath, and a 6-inch side-mounted solar telescope. Small tools and various levels are included for adjusting the apparatus. It is complete with a tripod painted red and a mahogany case.

 

TR 28, 30" Surveyor's Transit, John Roach, maker, San Francisco, CA, c. 1885.

This is a nice example of a smaller sized transit by this noted pioneer California maker. It has a horizontal circle to 30 seconds, and a half vertical arc to 1 minute, and a 3 5/8" compass needle. The transit is 10 1/4" high and has a telescope 7 3/4" long.