EAP1190/1/2

A set of hard-cover note books used to record the progress of research programmes carried out on a certain telescope. During this period of Boyden’s history, photography was the principal method of detecting and recording information. Typically, a piece of glass was coated with a photographic emulsion (a light-sensitive chemical), resulting in a “plate”, which was then attached to the telescope via a plate holder. The telescope was then trained on an object of interest and a mechanism (drive) was engaged to move the telescope so as to keep it locked on that object by compensating for the Earth’s rotation. The plate holder was then opened, allowing the collected starlight to shine on the emulsion. Usually, this was for an extended period, perhaps up to an hour, known as the exposure time. At the end of this time, the plate holder was closed and removed from the telescope. Later, in a dark room, the plate was developed (chemically treated) so that it no longer reacts to light. In this stable condition, the plate could then be examined with measuring devices, and the resulting numbers recorded for analysis. A unique sequential number is typically assigned to a plate, and this number is recorded next to the designation of the object of interest that was listed to be studied. It is these lists that are recorded in the log books of this series. These books are sometimes called registers, ephemeris, or more commonly, plate books. Each telescope, because of its physical construction, gives a unique view, and thus delivers photographs with specific characteristics. Thus, telescopes were said to deliver a “plate series”. So, for instance, the 13-inch Boyden Refractor telescope generated “Plate Series X”. The plate series is sometimes used in the title of a log book, while other books were identified by the name of the research project to be conducted (e.g. “Proper Motion Programme (1932-1934)”). In this series are also two particularly important logbooks: these contain daily records of weather conditions, covering the period 15 Aug 1927 to 31 Dec 1933. Taken together with the Meteorological Records series this represents a 40-year sample of meticulous weather records. While of limited astronomical value they are sure to be of interest to climate scientists.

n/a.

Extent: 26 volumes of astronomical and meteorological registers containing 969 pages, hard-back and covered with cloth.

Size and dimensions of original material: From (height 26cm, width 20cm, depth 1cm) to (height 33cm, width 21cm, depth 1cm).

Condition of original material: Generally in good condition. Three volumes have loosened covers and a few loose pages.

Custodial history: N/a.

Arrangement: N/a.

Alternative calendar and date: N/a, N/a

Author(s)/Creator(s): English.

Scribe(s): Latin.

Publisher(s): Left-to-Right.

Editor(s): Unrestricted.

Volume number: N/a.

Original institution reference: B.