SCIENCE. 



311 



tion, and the prices of those numbers which 

 are sold. A detailed chronological list of the 

 496 issues is then given, followed bj' a classi- 

 fied list under 29 heads, with some subdivis- 

 ions, and, finallj', hy an alphabetical index 

 to the Contributions, Miscellaneous collections 

 and Eeports of the Smithsonian, the Bulletins 

 and Proceedings of the National museum, and 

 the First annual report of the Bureau of eth- 

 nolog3^ Thus ever}' inquirj- that will probablj^ 

 be made is answered beforehand. Is my set 

 complete? Is this volume perfect? What 

 articles are there in this department of sci- 

 ence? In what volume or volumes has this 

 man written ? In what is this subject treated ? 

 How can I get them ? How can I procure 

 a set, or get the volumes as thej' are issued? 

 Indeed, if one must be critical, we should sa.y 

 that answers are provided for some questions 

 which onl}- an idiot could be expected to ask. 

 In the index, not only are references made 

 from the names of the authors, and from the 

 subjects of articles, but from the first words 

 of their titles, however insignificant they maj- 

 be. Thus we have such entries as Contribu- 



tions to history of fresh-water algae, Oriti- 

 cisms of Dr. .J. Hahn, Hints on public archi- 

 tecture. Knowledge of crj-ptogaraous plants. 

 Means of destroying the grasshopper. Method 

 of preserving lepidoptera. Narrative of the 

 Hassler expedition, and scores of others just 

 as unworkmanlike as these, — entries that 

 would malie the Index society stare and gasp. 

 In an ordinary book this might be overlooked ; 

 but it is unworthy of one which is intended to 

 be one of the monuments of the scientific 

 achievements of our country. It is true, these 

 articles are all indexed in their proper places 

 also ; so that the fault is, at worst, one of 

 surplusage. We have seen indexes in which 

 entries were made under A and The, and there 

 only. Mr. Rhees has not reached this length 

 of absurditj'. He may urge that there are 

 people who will look for the articles under the 

 words to which we have objected. It is dif- 

 ficult to over-estimate the mental left-handed- 

 ness of mankind, but Mr. Rhees is addressing 

 a scientific public. We should be sorry to be- 

 lieve that their training had produced no better 

 habits of thought than he seems to anticipate. 



WEEKLY SUMMARY OF THE PROaRESS OF SCIENCE. 



ASTRONOMY. 



Spectroscopic observations of tlie transit of 

 Venus. — Tacohini at Eome observed the first and 

 second contacts by means of the spectroscope, in the 

 manner first proposed by Young in 1869. He saw 

 the external contact 54 seconds earlier tlian liis col- 

 league Millosevisch, who observed with a telescope in 

 the ordinary way: the second contact (internal) he 

 observed 30 seconds earlier. A discussion shows that 

 the spectroscopic observations are superior in accu- 

 racy to the telescopic. An attempt was made to ob- 

 serve the contacts at Palermo in the same way by 

 Ricco, but it failed. At the moment when the planet 

 left the chromosphere, and its atmosphere was on the 

 slit of the spectroscope, both Tacchini and Ricco saw, 

 for a fraction of a second, one or two bands between 

 B and C, which could only have been caused by the 

 planet's atmosphere. — (Mem., spettr. Ital., Dec, 

 18S2.) 0. A. Y. [636 



Observations of the lunar crater Plato. — A 

 comparison by A. Stanley Williams of a large num- 

 ber of observations taken by himself and others in 

 1879-82 with a similar series taken in 1869-71 seems 

 to give evidence of change in this crater. Of thirty- 

 seven spots seen in the crater in 1869-71, sl.x; were 

 not seen in 1879-82; while seven, not seen during the 

 first period, were seen in the second. The mean visi- 

 bilities of most of the spots observed in both series 

 agree very closely, but eight show a decided variation 

 in brilliancy. Ainong the light streaks in the crater, 

 some change was noted, particularly in one which 

 was not seen at all during the first twelve months of 

 the first period, and is now larger and brighter than 



others previously seen. [This paper is to be con- 

 tinued.] — (Observ., March 1.) M. mcn. [637 



MATHEMATICS. 



Transformation of surfaces. — Professor Enne- 

 per, in this article, has reproduced the substance of 

 two previous articles which he has written upon the 

 same subject, with a number of additions. The par- 

 ticular transformations treated of are defined as fol- 

 lows : the corresponding points P and P, of two 

 surfaces S and S , are so related to a fixed point O, 

 that the plane through the points O, P, and Pj con- 

 tains the normals to the surfaces S and Si in the 

 points P and P,. Among other derived surfaces com- 

 ing under this head are the pedal and negative-pedal 

 surfaces, inverse surfaces, etc. A generalization of 

 Malus' theorem is given; viz., the surface separating 

 two homogeneous media is regarded from a given 

 point O; at a point P of the siuface, the ratio of the 

 sines of the incident and reflected rays is a function 

 of the distance O P : the reflected rays are then the 

 normals to a certain surface and its parallel. The 

 author discusses the problem of finding when lines 

 of curvature upon the given surface S correspond to 

 lines of the same kind upon the derived surface S,. 

 The results in this case are tolerably well known. — 

 (Math, ami., x.xi. 1883.) T. c. [638 



Geodesic polygons. — The results obtained by the 

 author, Otto Staude, in this paper, are for the most 

 part known ; but his method seems to be entirely new. 

 SI. Staude attempts, in a measure, to do for quadric 

 surfaces, by aid of hyperelliptic functions, what has 

 already been done for conies by the aid of elliptic 



