LITERARY NOTICES. 



129 



devoted, with numerous subheadings, to the 

 discussion of temperature and pressure and 

 their variations, evaporation, clouds, rain, and 

 snow ; winds, thunderstorms, and tornadoes, 

 and optical appearances. A full chapter is 

 given to the exposition of the construction 

 and meaning of weather maps, and another 

 chapter to the consideration of the import 

 of weather predictions. A short account 

 of river floods is given, and the method of 

 predicting river heights for a number of 

 points along the lower Mississippi River and 

 its tributaries. In all this a general view is 

 taken of meteorology, while climatology is 

 treated of only in its broad, general features. 

 The principal weather changes are described 

 as they occur in various parts of the world 

 in different seasons on land and sea, and 

 their causes are narrated as far as is known. 

 A collection of facts is given useful in form- 

 ing a conception of the phenomena of the 

 atmosphere as a whole, so as to enable those 

 with little time for consulting a multitude 

 of books to form a notion of the science of 

 meteorology as it is at present. 



The Birds of Eastern Pennsylvania and 

 New Jersey. With Introductory Chap- 

 ters on Geographical Distribution and 

 Migration. Prepared under the Direction 

 of the Delaware Valley Ornithological 

 Club. By Witmer Stone. Philadelphia : 

 Delaware Valley Ornithological Club. 

 Pp. 185, with Two Maps. 



The object of this volume which has 

 been prepared by a special committee ap- 

 pointed to collate the field notes of members 

 of the club is to provide these members 

 and ornithologists with a summary of our 

 present knowledge of the birds of the dis- 

 trict included, with regard to their abun- 

 dance, distribution, and time of occurrence. 

 Description of the birds and their habits 

 does not come within the scope of the work. 

 In the preliminary pages are given notes on 

 the geographical distribution of birds ; the 

 faunal areas of the region ; their physical 

 features and characteristic birds ; the dis- 

 tribution of winter birds ; a general discus- 

 sion of bird migration ; migration in the vi- 

 cinity of Philadelphia ; and birds found 

 within ten miles of Philadelphia conveying 

 copious information. The region is crossed 

 by the three faunal zones : the Carolinian, oc- 

 cupying the southeastern corner of Pennsyl- 



VOL XLV1I 12 



vania and the whole of southern New Jersey, 

 to the Hudson and beyond, with a bay up the 

 Susquehanna Valley ; the Alleghanian, occu- 

 ing the rest of the region, except the tops 

 of the higher mountain ranges and portions 

 of the elevated table land in the north cen- 

 tral part of Pennsylvania, where the Cana- 

 dian zone is represented. The passage from 

 the Alleghanian to the Canadian zone is, as 

 a rule, remarkably distinct, as the more 

 northern birds keep strictly to the virgin 

 forest. Where the forest has been removed, 

 the Canadian species for the most part dis- 

 appear. These three faunal zones are di- 

 vided into several well-defined regions which 

 differ more or less in their physical features, 

 and consequently in the character of their 

 bird life ; and these are described. 



Proceedings of the International Confer- 

 ence on Aerial Navigation, held in 

 Chicago, August 1, 2, and 3, 1893. New 

 York : The American Engineer and Rail- 

 road Journal. Pp. 429. 



The proposal to hold the conference of 

 which the proceedings are recorded in this 

 book originated with Prof. A. F. Zahm, of 

 Notre Dame University, who communicated 

 with Mr. C. C. Bonney, President of the 

 World's Congress Auxiliary, and interested 

 several other persons in the project. The 

 principal objects of the conference were to 

 bring about the discussion of some of the 

 scientific principles involved in the scheme 

 of aerial navigation ; to collate the results of 

 the latest researches ; to procure an inter- 

 change of ideas ; and to promote concert of 

 action among the students of this inchoate 

 subject. The programme involved, first, a 

 discussion of the general principles of the 

 subject, and more special discussions in Sec- 

 tions A and B, under the heads of Aviation 

 and Ballooning. Letters of co-operation 

 were received from experts or students of 

 the subject, and from the British Aeronautical 

 Society, the Aerial Navigation Society of 

 France, the Aviation Society of Munich, the 

 Imperial Aeronautical Society of Russia, and 

 the Aviation Society of Vienna. The ses- 

 sions were attended by about one hundred 

 persons, who seemed to take great interest 

 in the proceedings, and the discussions 

 brought out several investigators who had 

 been studying the subject or trying interest- 



