college authorities took up the subject anew and appointed a committee to form a plan for an observatory. Mr. Bond was then about to make a trip to England, and his friends Farrar and Bowditch procured for him a commission as agent of the college to obtain information as to the construction and instrumental equipment of the observatory at Greenwich, and to make such drawings as would be needed in constructing an observatory for the college. He was requested also to obtain from the makers the prices of instruments like the principal ones used at Greenwich. "He performed the service," says the writer of the sketch above referred to, "and reported in detail in the following year. That nothing practical came of it for a quarter of a century was not owing to the will but, comparatively speaking, to the poverty of the college.
"This result followed, however, that, upon his return, Mr. Bond constructed the model of an astronomical dome, the operative plan of which was the same as that of the great dome built in 1844, and which has been in satisfactory use at Cambridge to the present time. The chief peculiarity of its mechanism is in the method of rotation by means of smoothly turned spheres of iron. The dome rests on these at equidistant points, and, being set in motion by suitable gearing, the iron balls sustaining its weight roll along a level, circular track of iron, the circumference of which is equal to that of the dome. The method was unlike that previously in use. It appears to have been original with Mr. Bond, as is perhaps evinced by a remark in his report for 1848 referring to the matter: 'If carefully examined, it will be found that this arrangement is as perfect in theory as it is appropriate and convenient in practice.' Experience has shown that spheres of hard bronze are more serviceable than those of iron, and bronze is now used."
While Mr. Bond was abroad, he married, July 18, 1819, his cousin, Selina Cranch, of Kingsbridge, in Devonshire. Returning home, he went to live in Dorchester near his father's residence in a house which he bought. On these premises he erected, about 1823, a small wooden building which he carefully equipped for astronomical observations. This building is meant in the official reference to the "observatory at Dorchester" found in various publications. Its position, as given by Mr. Bond in 1833, was 0º 3' 15″ east of Harvard Hall in Cambridge.
Mr. Bond now advanced rapidly in his favorite pursuit. "As soon as his circumstances permitted," writes his son, "he imported more perfect apparatus from Europe, and continued to add to his collection until it was the best in the country." In his little observatory "no eclipse or occultation escaped him, though occupied in business during the day in Boston." After gathering
