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THE POPULAR SCIENCE MONTHLY. 



markable. No sucli brilliant gather- 

 ing of scientific, literary, and profes- 

 sional gentlemen has ever before as- 

 sembled on a festive occasion in this 

 metropolis. As his lecture-rooms, in 

 the various cities he has visited, have 

 been crowded by the most intelligent 

 and cultivated people, so the dining- 

 hall at Delmonico's was filled with two 

 hundred guests, many from abroad, and 

 representing the colleges and scientific 

 institutions of the country, together 

 with a large body of the most eminent 

 gentlemen of our cit^. The spirit of 

 the occasion was one of harmonious 

 enthusiasm for the distinguished pro- 

 fessor in whose honor it was made, and 

 of lively interest in the subjects and 

 ideas he represents. The speaking was 

 excellent, and, although graver and more 

 didactic than is customary at such times, 

 was yet by no means unexciting, and 

 met with the most cordial responses. 

 Of course Delmonico, prince of caterers, 

 lost no reputation in the elegant and 

 sumptuous repast which he furnished, 

 but the social and intellectual treat was 

 the great feature of the evening. Prof. 

 Tyndall made a happy address, in which 

 he explained the motive of his coming 

 to this country, the laborious character 

 of the work which his lectures involved, 

 and the reasons which compelled him 

 to decline the numerous urgent invita- 

 tions that have poured in upon him 

 from all directions, to lecture in the 

 cities of the interior and the West. "We 

 have no space now to refer to the sev- 

 eral admirable speeches that were made, 

 upon subjects variously connected with 

 the interests of science. They were 

 too valuable to be left in the incom- 

 plete shape in which the reporters gave 

 them to the newspapers, and they will 

 be shortly published as an appendix to 

 the little volume of his lectures which 

 Prof. Tyndall has carefully prepared, 

 and which will be given to tbe public 

 in a few days. 



LITERARY NOTICES. 



The Earth a Great Magnlt. . A Lecture 

 delivered before the Yale Scientific Club. 

 By Alfred Marshall Mater, Ph. D., 

 Professor of Physics in the Stevens 

 Technological Institute. Chatfield & Co., 

 New Haven. 



The author of this lecture is well known 

 to the scientific world, both iu this country 

 and Europe, as an original investigator in 

 the field of physics. He has made nu- 

 merous researches in various physical 

 branches, the results of which have been 

 published in the scientific journals, domes- 

 tie and foreign. He is now prosecuting 

 various inquiries at the Stevens Institute 

 of Technology, in Hoboken, where they have 

 the finest collection of physical apparatus 

 that can be found in any institution in this 

 country, if not in the world. Having won 

 his spurs as an original experimenter, and 

 established his place among those who ex- 

 tend and create scientific knowledge, he 

 now turns his attention to the work of dif- 

 fusing it among the people. It is common 

 to say that original investigators are not 

 good expositors ; and this is often true, but 

 it is also true that they are frequently the 

 very best of teachers. We have recently 

 had a conspicuous example of this in Prof. 

 Tyndall, and we now have another in Prof. 

 Mayer. The lecture before us is a model, in 

 its logical form, its copious and beautiful 

 experiments, and its lively and graphic lan- 

 guage. As an exposition of the elements 

 of terrestrial magnetism in a compressed 

 and readable form, it is perfect. Triibner, 

 of London, has caught it up and issued it ; 

 and the London and Edinburgh Philosophical 

 Magazine, the first scientific authority, has 

 reviewed it in so just and discriminating a 

 way that we cannot do better thau to quote 

 a portion of its statement : " This is the 

 report of a lecture delivered before the Yale 

 Scientific Club on February 14, 1872, in 

 which the lecturer proposed to present to 

 his audience ' one prominent truth in simple 

 and striking experiments.' The truth which 

 is kept steadily before the mind throughout 

 the lecture is, that the earth is a great mag- 

 net ; and this truth is developed step by 

 step by experiments of the most conclusive 

 kind, each having been rendered distinctly 



