Images(4)

watchmaker's transit

Datecirca 1880

Inventory Number1997-1-1800

ClassificationTransit

Subject

Maker John Bliss & Company 1857 - 1956

Owner William Bond and Son fl. 1793 - 1977

Owner W. H. Stedman fl. 1908

Cultural Region

Place of Origin

Place of Use

Dimensionswith telescope horizontal: 23.6 x 20.1 x 29.5 cm (9 5/16 x 7 15/16 x 11 5/8 in.)

Material

DescriptionA refracting telescope is mounted on two conical arms that are carried in a cradle. The cradle is brass and attached to the mounting struts.

At the end of one of the arms, there is a divided circle. It is graduated 0-90-0-90-0 degrees with northern and souther halves of the circle indicated by initials at the zero points. A knurled thumb screw is in the center of the wheel and permits one to adjust the rotation of the wheel with respect to the orientation of the telescope. A reading mark is on a semicircle of brass attached to the upright strut.

The telescope has a dust cap on the objective. A drawtube for the eyepiece provides focus. The eyepiece has a solar diagonal attached with a wheel of filters. The tube has cross hairs. (The telescope and altitude circle are shiny brass, having been cleaned by Ebenezer Gay in 1980. The reading mark and scale were to be resilvered, but this was never done.)

The mounting is cast. It consists of two, open triangular uprights and a base of two open concentric circles. The base has two pointy feet and one shiny brass leveling screw foot. The castings have been painted yellow.

In Collection(s)

Clocks and Watches

Signedunsigned

Inscribedassembly mark under screw in center of scale: 8

Curatorial RemarksRecords state that this watchmaker's transit came from the store of William Bond & Son at Park Street, Boston. An old tag with the instrument reads: p 16 / June 22 1908 / W. H. Stedman / Bliss / Transit The tag is circa 1908. David P. Wheatland received the instrument from Richard Mills of Exeter, New Hampshire in 1969. Mills donated some Bond medals to the Collection that same year. Although it seems more likely that Bond and Son had the transit first and it later passed into Stedman's hands, the opposite may also be true.

FunctionAn astronomical transit is used with a clock to measure the altitude and time that a star or celestial body crosses the meridian at a specific location. This gives the declination and right ascension of the star, which are that star's coordinates in the sky. The information can also be used to find the longitude of a location if one has knowledge of when the meridian crossing would happen at the zeroth longitude.

If one has a table listing when a particular star is to cross the meridian at a given location, one can use the transit to find the time at that location at that moment. For this reason, small table top transits like this one were often used by watchmakers to check the running of their watches and clocks.

Medium-sized and larger portable transits were used in the field by astronomers when they went on expeditions to observe an eclipse or Transit of Venus.

ProvenanceWilliam Bond and Son; W. H. Stedman; ...; Richard Mills, Exeter, NH; David P. Wheatland, 1969.

Historical AttributesThis watchmaker's transit belonged to and was used by William Bond & Son of Boston, makers and raters of chronometers and precision clocks. From about 1863, the financial records of Bond & Son show that the firm did a lot of business for John Bliss & Co, who also made chronometers.