“This has been supplied by replacing the original clock of the great equatorial of the observatory by a new one, operating on the principle of the spring-governor. Immediately upon its completion, a new series of experiments was commenced. These have been successful in transferring to the plate by the collodian process, images of fixed stars to the fifth magnitude, inclusive, with singular and unexpected precision. The most remarkable instances of success are the simultaneous impressions of the group of stars composed of Mizar of the second magnitude, its companion of the fourth and Alcor of the fifth magnitude. The following measurements of the angular distance of the companion from Mizar were taken from the plates.”
THE GOLD MEDAL; REVERSE SHOWING SIR WILLIAM HERSCHEL’S 40-FOOT TELESCOPE.
A tabulated statement follows in the paper, giving dates from April 27 to May 8, with measurements from 13 photographic negatives produced on the respective dates. The mean for distance is 14.49 seconds, and for angle of position, 147°.80. For the same stars observed in the usual way, Struve’s mean of six observations is, for distance, 14.40 seconds; for positions, 147°.40.
Mr. Bond’s comments are: “The photographic method has thus in its first efforts attained the limit of accuracy, beyond which it is not expected the other can ever be sensibly advanced.
“Should photographic impressions be obtained from stars between the sixth and eleventh magnitudes as has already been done for those between the first and fifth, the extension given to our present means of observation would be an advance in the science of stellar astronomy of which it would scarcely be possible to exaggerate the importance.”
Mr. Bond made important contributions to the literature of the science both in its mathematical and practical departments. Among the more notable of the former was a paper on cometary calculations and the method of mechanical quadratures, valuable in various respects, and notable in having anticipated an important improvement afterward given independently by Encke; also a paper on the use of equivalent factors in the method of least squares. He wrote a monograph covering observations of Donati’s comet of 1858, for which he was awarded the gold medal of the Royal Astronomical Society and was the first of his countrymen to obtain that distinction. He began a paper on the nebula in Orion, which he did not live to complete, though during his prolonged last illness he continued his labors upon it, and dictated to an amanuensis long after strength to write had gone from him.
This paper was afterwards finished by Prof. T. H. Safford, then of Harvard, now of Williams College observatory. A biographer says of Mr. Bond: “Science to him was not a pastime but a serious calling, to be pursued with the utmost conscientiousness and singleness of purpose. That he did so much and did it so well, during the few years allotted to him, must have been partly owing to an extreme reluctance to dissipate his powers by beginning new works while the old were still unfinished.” He received the honorary degree of A.M. from Harvard in 1853.
PRESIDENT JOSIAH QUINCY.