A GOOD MID 19TH-CENTURY DIPLEIDOSCOPE BY E.J. DENT
constructed in oxidised-brass, signed on the polished-brass cap, countersigned and numbered to side E.J. Dent Patentee 624, levelling screw, bubble level and compass, contained within original mahogany box, together with a copy of Dent's Table for the equation of time, 1846 to accompany his new meridian instrument, and a note attributing provenance to Captain Thomas Levois, in the slave trade most of his time, the lid containing polarising filter. Overall measurements -- 6in. (15cm.) square

The dipleidoscope was patented in 1843 by James Bloxam and marketed by Edward Dent for timing the meridian transit of the sun. The mirror cell contains a hollow, right-angled prism, with two sides silvered and one of glass. The meridian transit was determined by the coincidence of two images of the sun by single and double reflection, one from the top glass and the other from both mirrors. With the base properly levelled and oriented, the meridian transit could be read to seconds.

Condition Report
Cap has some circular (?)polishing marks; instrument in fine condition; corner of compass glass missing. Good overall condition.

We are pleased to provide you with a general report of the condition of this property. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Charles Miller Ltd is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD “AS IS” IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE.