Page:Popular Science Monthly Volume 6.djvu/127

Rh friends the burden of your lifelong helplessness?'

"I urge the separate higher education of females solely upon physical grounds. My experience has forced me to this. I have a record of my former pupils who stood high in their classes, who did their work with seeming ease, but who have been unable to teach, and now confess that they date the beginning of their present sufferings to the continuous labor of school. I have in my mind, as I write, the case of a young lady from Tioga County, now residing in this city, who stood foremost in her class, and without apparent effort, but who has never been in sound health since her graduation; and she attributes her present condition to the insensible exhaustion of her class-work. Yet she would have been the very last to confess overwork while a pupil; and I do not think that either she, or her teachers, then suspected it."

is the first of a series of three volumes to be published for the joint authors, who are both skillful and able astronomers, known in the scientific world by various important researches. This volume treats of the observatories of England alone, and it is to be followed by two others treating of those of Scotland, Ireland, the Continent, and America.

The design of the work is most excellent, and its execution is thoroughly good, as indeed might have been anticipated. In brief, the plan of the authors has been to give a short history of each of the many institutions devoted to practical astronomy, with a sketch of the life and works of each of the directors who has been in charge of it, as well as an account of the principal instruments and the uses to which they have been devoted.

Quite a number of very good woodcuts are supplied, which give perspective views of some of the most important instruments, and these alone lend great value to the book. Many of these cuts are derived from engravings given in the publications of the various observatories, and they are therefore accessible to all who can consult any of the great libraries; but the collection of these into one volume is a great convenience.

Quite a number of the cuts, however, must have been copied from photographs privately distributed, which, of course, are not generally accessible, nor widely known, and for the reproduction of these we cannot be too grateful. We may instance the extremely interesting cut of Mr. Newall's great telescope of 25 inches aperture (made by Cooke, of York), which was the largest refractor in the world until the mounting of the Clark telescope at the United States Naval Observatory at Washington, in 1873.

A propos of large telescopes, the authors tell us that the two large disks of glass (30 inches in diameter) which have been in the possession of the Paris Observatory since 1855, are shortly to be ground into lenses and mounted, so that, provided the operation of grinding is successful, and no unknown flaws in the glass exist, Paris will soon have a larger equatorial than any now mounted.

Americans, however, may console themselves with the thought that the magnificent gift of Mr. Lick, of San Francisco ($700,000), will soon become available "to construct a more powerful telescope than any now in the world," and they may safely trust to the artistic skill and to the scientific sagacity of the Clarks, to whom the work will undoubtedly be confided, to make the most perfect instrument yet known.

The book treats largely, too, of the history of the private observatories of England, and it is no small convenience to have gathered into one volume material which, if in print at all, is scattered through many volumes of rare periodicals and books.

In this volume 50 pages are devoted to the Observatory of Greenwich alone, and then follow accounts of those observatories which belong to universities, to learned