396 



SCIENCE, 



[Vol. IV., No. 90. 



LETTERS TO THE EDITOR. 



*** Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



American geological railway-guide. 



I have commenced revising my geological railway- 

 guide for a second and much improved edition. I 

 should be glad if persons who have used the book, 

 and made notes of corrections and additions, would 

 send such corrections or additions to me ; or, if it will 

 be a saving of labor, it will be a great favor to me if 

 they will send me their copies of the book by mail; 

 and I will return them, and refund all postage. 



James Macfaklank. 



Towanda, Perm. 



A voider use of scientific libraries. 



In Science for Oct. 3, your editorial calls attention 

 to the need of making scientific libraries more widely 

 useful. Perhaps some of your readers will be glad to 

 know the liberal policy of the Boston society of natu- 

 ral history. The society is willing to send such books 

 as can be replaced, to students in any part of the coun- 

 try, at their expense of course ; asking from strangers 

 a deposit of twice the market-value of the books so 

 sent, as a guaranty against loss. This is an example 

 which may well be followed by all special libraries. 

 Edward Burgess, librarian. 



Boston, Oct. 17. 



Eye-pieces of the meridian circle at Washburn 

 observatory. 



In vol. ii. of the Publications of the Washburn ob- 

 servatory, p. 28, I bave incorrectly said that the eye- 

 pieces furnished by tbe Messrs. Repsold of Hamburg 

 with our meridian circle were not Steinheil achromat- 

 ics. I made this statement after receiving a letter 

 from the firm of Steinheil & Co., which I erroneously 

 supposed to convey this meaning. 



Edward S. Holden. 



Madison, Wis., Oct. 14. 



THE OCTOBER MEETING OF THE 

 NATIONAL ACADEMY OF SCIENCES. 



The autumn session of the National acad- 

 emy was held last week at Newport, R.I. The 

 time and place did not combine to a very suc- 

 cessful gathering, the hotels having just closed 

 their doors upon the exodus of summer visit- 

 ors, while many a college- professor was still 

 too much entangled in the work of an opening 

 year to be able to leave his duties. At the 

 beginning of the meeting on Tuesday, indeed, 

 it looked as though a two-days' session was all 

 that could be counted on ; but so mam' of the 

 papers provoked discussion, that the session 

 lasted, as usual, into Friday, with only half an 

 hour devoted to business ; and the number of 

 papers finally offered surpassed that of the 

 year before. Twent} T -three of the ninety-three 

 members were present, and twenty-three papers 

 were presented. 



The meeting was not marked by an}* paper 

 of exceptional importance ; but most of them 

 were of general interest, and provoked ex- 

 tended discussion. Perhaps that which awak- 

 ened the liveliest interest was the one in which 

 Dr. E. B. Tylor of Oxford, who addressed the 

 academy by request, gave his observations 

 upon our native tribes, and called attention to 

 the parallelism of their customs and those of 

 widely distant races. He dwelt at length upon 

 the distinction which should be drawn between 

 the origin of identical customs in separate 

 groups of men, some of which are due to the 

 descent of such groups from one primordial 

 stock, and some have arisen spontaneously from 

 similar psychic conditions. To the former, Ray 

 Lankester had applied the term -homogeny.' 

 and, to the latter, ' homoplasy.' He asked the 

 academy to tell him to which class so compli- 

 cated a symbol as the pentagram belonged, 

 which is used both b} T the Indians and the 

 Asiatic astrologers. Professor Hilgard thought 

 that such a s} T mbol would arise spontaneously, 

 as only in that form could a stellar figure be 

 produced by the use of one continuous line. 

 Major Powell believed that a third class should 

 be added, to include arts and customs borrowed 

 from neighbors, — a class which he was accus- 

 tomed to call ' origin b} T acculturation.' 



Among the physical papers, astronomy, as 

 usual, held a leading place. Professor Langle}* 

 offered the acadenry a continuation of his ob- 

 servations on the temperature of the moon's 

 surface, as studied by the bolometer, showing 

 that it must be even lower than two hundred 

 degrees below zero, Centigrade. Professor 

 Valentiner of Carlsruhe, by invitation of the 

 academ}', gave in his own language an account 

 of the meridian-work he intended to undertake 

 at the observatory, recently removed from 

 Mannheim, and the installation of which would 

 be completed by the middle of next year. His 

 principal work was to be the observation of all 

 stars, up to the eighth magnitude, between the 

 equator and 22° south latitude, and he hoped 

 to accomplish the task in twelve years. Dr. 

 Peters of Clinton stated what progress he had 

 made in determining the stars in the star-cata- 

 logue of Ptolemy's Almagest, and gave a very 

 interesting account of his studies of the manu- 

 scripts extant, and the errors which had crept 

 into them, exhibiting photographs of some 

 codices. 



Mr. C. S. Peirce explained some of the 

 errors still needing correction in pendulum 

 observations, particularly such as were due to 

 the flexure of the pendulum. He presented 

 the outline of a scheme for a gravitation sur- 



