THE reader familiar with astronomical literature will doubtless remark a certain resemblance between the plan on which this book is written and that of Fontenelle’s “Conversations on the Plurality of Worlds,” a French classic of the eighteenth century. The author freely acknowledges that it was the recollection of the pleasure which the reading of Fontenelle’s book gave him, years ago, that led to the adoption of a somewhat similar plan for this description of the moon. But, except that in both cases the conversational method is employed, no great likeness will be found between what is here presented and the work of the witty Frenchman.
Having been invited by the Messrs. Appleton & Co. to prepare a small volume, to be based on a series of lunar photographs representing the moon as it appears on successive evenings during an entire lunation, the author felt that the work should be made as entertaining as possible. He has, therefore, avoided technicalities, while endeavoring to present all the most essential facts known about our satellite. What he has written is intended for the general reader, who desires to learn the results of the great advances in astronomy without being too much troubled with the scientific methods by whose aid those results have been reached.
This is the first time, as far as the author is aware, that a series of lunar photographs, showing our satellite in its varying aspects from New to Old Moon, has been presented in a book, accompanied with a description of the mountains, plains, volcanoes, and other formations shown in each successive photograph. The reader is enabled to place himself, as it were, in an observatory of the first rank, provided with the most powerful apparatus of the astronomer, and, during an entire month, view the moon in her changing phases.
The photographs here reproduced were made at the Yerkes Observatory, and the most grateful acknowledgments are tendered to Prof. Edwin B. Frost, its director, for generously consenting to their use for this purpose. He could only have been induced to do so by his desire to see the fruits of the admirable work accomplished by his associates enjoyed by an ever-widening circle.
The series of photographs representing the moon on successive evenings were taken with the 12-inch telescope of the Yerkes Observatory by Mr. James Wallace, who employed a color filter that he constructed specially for this telescope, which possesses a visual and not a photographic objective. The larger scale photographs, representing certain selected regions on the moon, were taken by Mr. Ritchey, now of the Carnegie Solar Observatory at Mount Wilson, California, with the great 40-inch telescope of the Yerkes Observatory. It is unnecessary to speak of the extraordinary quality of these photographs, which have been admired by astronomers in all lands.
It should, perhaps, be added that while the director of the Yerkes Observatory has shown confidence in the author by intrusting to him the use of these photographs, yet, neither Professor Frost, nor Messrs. Wallace and Ritchey are in any way responsible for the statements made in this book. The author has taken pains to be accurate, but if any errors of fact or opinion have crept in, he alone must be blamed for them.
GARRETT P. SERVISS.
CHÂTEAU D’ARCEAU,
CÔTE D’OR, FRANCE, JUNE, 1907.