PREFACE

Summary

The progress of astronomical discovery was never more rapid than during the last fifteen years. Within this period, the number of known members of the planetary system has been more than doubled. A planet of vast dimensions has been added to our system; thirty-six new asteroids have been discovered; four new satellites have been detected; and a new ring has been added to Saturn.

It is especially gratifying to note the progress which the last few years have witnessed in the United States, both in the facilities for observation, and in the number of active observers. It is but twenty-five years since the first telescope, exceeding those of a portable size, was imported into the United States; and the introduction of meridional instruments of the larger class is of still more recent date. Now we have one telescope which acknowledges no superior; and we have several which would be esteemed worthy of a place in the finest observatories of Europe. We have also numerous meridional instruments, of dimensions adequate to be employed in original research. Our own artists have entered successfully upon the manufacture of refracting telescopes of the largest size, and have received the highest commendation from some of the best judges in Europe. These instruments have not remained wholly unemployed. At the observatories of Washington and Cambridge, extensive catalogues of stars are now in progress; while nearly every known member of our solar system has been repeatedly and carefully observed.