638 



SCIENCE. 



[N. S. Vol. III. No. 69. 



In the first and second chapters the author ex- 

 plains, In a very clear manner and in a non- 

 technical language, the properties of wires 

 carrying currents of electricity. The particular 

 features treated are those which have a bearing 

 on danger from fire and the proper proportion- 

 ing of wires to avoid such danger. Chapter 



III. deals with the series, the multiple and the 

 three-wire systems. There are excellent dia- 

 grams showing what these systems are, and the 

 text explains how they are operated. Chapter 



IV. gives a brief account of methods of wiring, 

 particular attention being given to the reasons 

 which make the conduit system the most desir- 

 able for the better class of modern buildings. 

 The remaining chapter gives the National code 

 of rules for wiring as applied to Central Stations, 

 High-Potential Systems, Low-Potential Systems, 

 Alternating Systems, Electric Railways and 

 Batteries. These rules are all quoted in full, 

 and each rule is followed by a full explanation 

 of the reasons for its adoption and the dangers 

 which it is the object of the rule to avert. The 

 rules contain many technical words which are 

 explained. It is evident that this is the kind 

 of information which will conduce to the more 

 general carrying out of these rules in practice. 

 The house owner will see that they are de- 

 signed to protect this property, and not simply 

 to annoy him by useless restrictions. The book 

 is well 'written and contains information that 

 no house owner can afford to ignore if he is 

 called upon to deal with electric wiring. 



Francis E. Nipher. 



SCIENTIFIC JOURNALS. 



THE AUK. 



The Auk for April is a number of rather 

 more than usual interest. The opening article, 

 by William Palmer, ' On the Florida Ground 

 Owl {Speotyto floridana),' treats in detail of the 

 peculiar distribution and breeding habits of this 

 hitherto little known species, and is illustrated 

 by a colored plate of the bird, a diagram of one 

 of its breeding sites, and a cut showing in sec- 

 tion one of its burrows. Mr. F. A. Lucas 

 writes of ' The Taxonomic Value of the Tongue 

 in Birds,' illustrated with figures of the tongue 

 in 12 species, showing the relation of its struc- 



ture to the food habits in different groups of 

 birds. 



Miss Florence A. Merriam has interesting 

 ■ ' Notes on Some of the Birds of Southern 

 California,' and the well-known artist, Abbott 

 H. Thayer, has a very suggestive paper on 

 ' The Law which Underlies Protective Colora- 

 tion,' with cuts in the text and five full-page 

 photographic illustrations. In short, Mr. 

 Thayer's newly discovered law is to the effect 

 that ' animals are painted by nature, darkest 

 on those parts which tend to be most lighted 

 by the sky's light, andmce versa.' This is illus- 

 trated by a series of ingenious experiments 

 with the Riiffed Grouse and Woodcock, show- 

 ing that when the darker 'protective' tints of the 

 upper surface are artificially extended over the 

 lighter lower parts the bird becomes ' com- 

 pletely unmasked.' The artificial extension of 

 the top colors over the lower parts destroys the 

 counter-gradation of colors imposed by nature 

 and forces the bird's solidity to manifest itself. 



Dr. Louis B. Bishop describes a new Song 

 Sparrow and a new Horned Lark from North 

 Dakota, and George K. Cherrie a new Night- 

 hawk from Costa Rica. Witmer Stone pub- 

 lishes a revision of the North American Horned 

 Owls, describing also a new species. Some six- 

 teen pages are devoted to a critical examination, 

 by J. A. Allen, of Giitke's ' Heligoland as an 

 Ornithological Observatory, the Result of Fifty 

 Years' Experience ' — a book that has attracted 

 wide attention and in general has received high 

 praise. Mr. Allen, however, shows that its 

 merits have been often greatly overrated, and 

 its faults either wholly overlooked or very 

 leniently mentioned. While ' Heligoland ' is 

 an important contribution to the literature of 

 ornithology, " it contains much that is set forth 

 as fact which proves on close examination to be 

 mere conjecture." This is especially true of 

 Chapter IV. , on the ' Velocity of the Migration 

 Flight,' where, on very slight evidence and in 

 opposition to an abundance of rebutting testi- 

 mony, it is claimed that most birds perform 

 under normal conditions their migratory jour- 

 neys in 'one uninterrupted nocturnal flight, * * 

 accomplishing a distance of at least 1,600 geo- 

 graphical miles within the space of nine hours. ' 

 He even considers that the Red Spotted Blue- 



