April 23, 1886.] 



SGIEXCE. 



365 



The coincidence between the lines of scarlet- 

 fever and diarrhoeal diseases, to which attention 

 was directed in the number of Science already 

 referred to, is equally marked this month : in 

 fact, they run so nearly parallel, that it is often 

 impossible to distinguish them. The summer 

 mortality has not yet commenced to show itself, 

 but many weeks will not pass before we shall see 

 its line gradually rising higher and higher, until 

 it reaches its height in midsummer. 



The meteorology for the month presents some 

 interesting features. The rainfall was consider- 

 ably less than in February ; in the latter month 

 4.89 inches having fallen, while during March 

 there were 2.83 inches, the actual time in which 

 this amount fell being 2 days 20 horns 40 minutes. 

 During the sixteen yeafs 1869-84 this amount was 

 exceeded in every year but four, so that March, 

 1886, was, in comparison with other years, a dry 

 month. 



Another point of interest in the meteorology of 

 March of this year is the absence of snow. But 

 an inch fell during the entire month, and that on 

 the twenty-seventh day. During the period of 

 sixteen years already referred to, so small an 

 amount fell in only five years, while in some of 

 the years the quantity was very great ; notably in 

 18T0, when 9.63 inches fell ; in 1875, 15.25 inches ; 

 and in 1883, 10 inches. 



It will be remembered that in February the 

 highest reading of the thermometer was 52° F., 

 and the lowest — 4° F. In March the maximum 

 temperature was 62° F., and the minimum 8° F., 

 the monthly mean for March being some 31° 

 higher than that for the preceding month. 



The population of the city of New York on 

 March 1 was estimated to be 1,424,903, and in- 

 creases presumably 799 each week. 



POPULAR ASTRONOMY. 



In the ' Story of the heavens,' Dr. Ball presents 

 to the popular reader an extremely entertaining 

 account of the discoveries, researches, facts, and 

 theories, of a science which, in a general way, is 

 of interest to a larger class of people than any 

 other department of learning. The book is spe- 

 cially directed to the non-astronomical ; the style 

 is strong and vigorous ; and many points are 

 elucidated in so striking a manner that even the 

 professional astronomer, if modest enough, can 

 get many a good suggestion from it. 



Ambiguities and misstatements of fact are quite 

 entirely absent. Dr. Ball appears to be rather 



The story of the heavens. By Robert Stawell Ball. 

 London, Cassell, 18S5. 8°. 



less certain than the facts warrant, that the sun- 

 spots are depressions ; and he would find few 

 astronomers, in this country at least, who would 

 agree with him that the late Professor "Watson 

 probably discovered an intra-mercurial planet or 

 planets during the eclipse of 1878. In parts of 

 his work the historical method is pushed to the 

 extreme. The complex theories of our astronomy 

 will doubtless appear in the least difficult form if 

 viewed in the light of the logical order of their 

 dawning upon the philosophic mind ; but the at- 

 tempt to insist on this method of treatment ap- 

 pears, in some instances, to have led Dr. Ball into an 

 unnecessary multiplication of wordy paragraphs. 

 While thoroughly interesting and dehghtfully 

 told, his ' Story ' is, for all that, a pretty long one ; 

 and we cannot but think that it would have been 

 better received, not to say more carefully read, if, 

 by some such omissions as these, Dr. Ball had 

 sooner brought it to a close. 



Works on popular science, often a mere retailing 

 at second or third hand of the labors of the pro- 

 fessional investigator, are not infrequently filled 

 with such misrepresentations of these labors as to 

 be utterly misleading to the learner, not to say 

 wrath-inspiring to those scientists whose work 

 forms the unwilling subject of the story. Dr. 

 Bali commits no offence of this sort : he is one of 

 these investigators himself, but his own researches 

 are not brought into undue prominence. We should, 

 however, take exception to his account of the 

 transit of Venus of 1882 as seen at Dunsink, 

 where no observations of marked importance 

 could be made, — an account which, therefore, 

 cannot give a sufficient and characteristic view of 

 the magnitude of the very extended operations 

 conducted elsewhere on that occasion. We find 

 no allusion to the abundant series of photographs 

 of that transit, obtained by the American parties, 

 which, it is safe to say, constitute the most im- 

 portant and successful record of a transit of 

 Venus ever secured. 



In some other parts, also, the ' Story of the 

 heavens' is not well balanced. There is, per- 

 chance, the best of reason for being dissatisfied, 

 or rather unsatisfied, with the present state of 

 solar research. Id the chapter on the sun, we 

 find an exceptionally full description of the solar 

 spots ; but the question as to what they are is dis- 

 missed in a word. The progressive theories of 

 the constitution of these objects form a most im- 

 portant contribution to the history of astronomy ; 

 and many a page in the book might better have 

 been devoted to an outlined statement of these 

 theories, and of what the spots, to say the least, 

 seem likely to be. We should make much the 

 same criticism of the author's treatment of that 



