TELLURIUM & LUNARIUM BY BENJAMIN MARTIN, LONDON, CA 1767

Gilt-brass drum containing double-cone gear-work for operating both the tellurium and lunarium, top plate of drum engraved with central sun motif surrounded by zodiac degree and calendar scales. Circumference of drum cut with 274 teeth, the mechanism operated by two ivory handled hand-cranks mounted onto side of drum. The whole mounted onto a 14 1/2 inch tall turned brass column with folding tripod base; lunarium with small geared earth and moon in ivory, each rotating above with separate rings representing the daily rotation of the earth, and phases of the moon; tellurium with 3-inch terrestrial globe signed in cartouche "A New Globe of the Earth. By James Ferguson," mounted with silver meridian, mounted above geared mechanism with pointer and plate indicating the hour of the day; complete with small and large brass spheres representing the sun, as well as original oil lamp that can be used in place of the sun spheres, pointer extending from sun to globe indicating the direction of the sun's rays. Housed in the original locking mahogany case. 

A Measure of Time. 25th Anniversary. Trevor Philip & Sons, p. 30; Instruments of Science: an Historical Encyclopedia, p 467

A VERY RARE AND EXCELLENT EXAMPLE OF BENJAMIN MARTIN'S FAMOUS TELLURIUM & LUNARIUM. Benjamin Martin (c. 1705-1782) was one of the leading sellers of scientific instruments in the 18th century. A very successful businessman, he took over the globe-making business of James Ferguson (maker of the globe in the tellurium portion of the present instrument) in the 1750s. Martin was renowned for his excellent planetary models, and in the 1760s he introduced two special models; the tellurian, which shows the annual motion of the Earth around the sun, and the lunarium, which shows the motions of the moon around the earth, as well as of the moon and earth around the sun. The present instrument is an excellent example of this innovative instrument. Martin's work was world renowned, so much so that he was commissioned by Harvard University to produce a suite of instruments for their collections.