Surveyor's transit by Edmund Draper
A brass transit, ca. 1860's, marked on the compass face "Edmund Draper, 208, Philadelphia, and with the distinctive Draper 7 pointed star at north. The compass needle is a 4 3/4 inch blued vertical bar. The silvered compass ring is graduated in 1/2 degrees. A single horizontal vernier with beveled scale is mounted 35 degrees E of S (E and W are inverted). The horizontal clamp and tangent screw are mounted under the plate and crossed straight levels are mounted above. A full vertical circle with vernier, tangent screw and clamp are provided. The 10 inch erect image telescope is fitted with rear screw focus for the cross hairs and front rack focus of the objective. A graduated level is hung from the telescope. The crosshairs are located beyond the trunnion - an uncommon location seen on some of the earliest American transits. The unique Draper shifting head and 4 screw leveling base is included, as is the original tripod. Draper introduced this feature in 1859, allowing the instrument to be shifted horizontally in any direction. While he began making instruments in 1832, he apparently did not use serial numbers until around 1860. This instrument, No. 208, is the earliest we have come across. Draper died in 1882, having been in the instrument making business in Philadelphia for 50 years. The interesting box has a raised portion on the lid to accomodate the instruments vertical circle, and, has dovetailed joints. Inside the lid is a trade label for the Philadelphia firm of "James W. Queen & Co., Opticians". Many early Queen transits were made by Young (unsigned), but they apparently sold Draper instruments too. Queen also refurbished and sold used instruments by various makers, so it is not clear whether this instrument was originally retailed by Draper or Queen.
The instrument is complete and all movements function. the brass is uncleaned and has a fairly uniform dark patina. The telescope focusses and the cross hairs are present. The fitted, hand-dovetailed box is in very good condition. It's leather strap is broken. The tripod is in very good condition, noting one leg tip missing.
1. There is a weld at the end of the trunnion opposite the vertical circle. While the repair does not seem to affect the vertical motion, it is unsightly.
2. One of the two levels on the plate has a cracked glass.
3. The horizontal tangent screw has been remounted incorrectly. It works, but is not properly aligned and is secured with only one screw. A new hole was drilled in the plate approx 1/4 inch out from the original hole, instead of removing the broken screw. Restoration would require removing the original broken screw in the plate and mounting the bracket in its original position.
4. One of the screws under the plate, attaching the A frame, and the screw on the trunnion end on the same side are modern replacements.
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