The 15-inch equatorial was set up on June 23 and 24, 1847. Certain nebulæ and the planet Saturn were the first subjects of study. Discoveries of importance were made in each field of investigation. The report of the visiting committee for 1848 notes the discovery by Prof. Bond on Sept. 19 of that year of the eighth satellite of Saturn, and speaks of it as “the only addition to the solar system ever made on the continent of America.” The few years immediately following the date of the great telescope may be called the romantic period in the history of the observatory. There was no instrument on this continent to be compared to it, and it had but one equal in Europe. While the director of the observatory kept cool enough to utilize it to the utmost, he manifestly shared in the enthusiasm. One of the earliest to inquire what could be seen by it was Edward Everett, president of the college from 1846. Prof. Bond responded by letter on July 26, 1847, named several matters and ended by saying: “But I must recollect that you require of me only a brief account of our telescope. The objects revealed to us by this excellent instrument are so numerous and interesting that it is difficult to know where to stop.” On Sept. 22 following Prof. Bond wrote to the president: “You will rejoice with me that the great nebula in Orion has yielded to the powers of our incomparable telescope.” He explains the reason for his rejoicing by saying that this nebula and that of Andromeda had hitherto been the strongholds of the “nebular theory,” or the theory that the nebulæ are masses of matter in process of condensation into systems. Now, the mass in Orion which, he said, had defied the telescopes of both the Herschels, and, at first, that of Lord Rosse, had been resolved into innumerable distinct points of light, or separate stars, by the Cambridge refractor, whose only competitor in the search was Lord Rosse’s instrument, “the largest reflector in the world.” The phrase “incomparable telescope” was warranted. Nor does the didactic suggestion of the proverb about the new broom apply; for more than 30 years afterwards the present director of the observatory had occasion to say: “In 1877 besides the photometric measures of the satellites of Mars, a series of measures for their positions was also made. The number of these observations was second only to that obtained with the great telescope at Washington.” Of the work done two years later, he says: “Of the satellites of Mars 1348 measurements were made, Deimos being last seen at this observatory as it gradually receded from the earth. This is remarkable, as our telescope has entered into competition with the largest telescopes of the world, some of which admitted two or three times as much light.”