October 9, 1914] 



SCIENCE 



525 



years. It will long be a standard reference 

 book for the region it covers, while many of the 

 analytical tables and keys will be of use else- 

 where. The illustrations, particularly the 

 volume of plates, are very fine and of inestima- 

 ble value. It is rare indeed that better photo- 

 graphs of starfishes are seen. The Harriman 

 Alaska Expedition did much to advance our 

 knowledge of the zoology of the northwestern 

 American coast, and the volumes containing 

 its results are notable for contents and appear- 

 ance alike. But among them all, none take a 

 higher rank or make a better impression than 

 do these volumes on the starfishes, by the 

 Nestor of American systematists. 



Hubert Lyman Clark 

 Museum of Comparative Zoology, 

 Cambridge, Mass., 

 June 17, 1914 



The Weather and Climate of Chicago. By 



H. J. Cox and J. H. Armington. Bulletin 4. 



The Geographic Society of Chicago. 



The authors, for many years official fore- 

 casters at Chicago, are to be congratu- 

 lated upon the completion of a laborious 

 piece of self-imposed work. The volume is 

 essentially the station Means Book in extenso 

 with stress laid upon unusual and extreme 

 conditions. Beading between the lines, one is 

 conscious of the effort to deduce definite laws 

 bearing upon forecasting, but the hope is not 

 realized and indeed we are told that " careful 

 examination fails to afford any clue by which 

 the nature of a season or year may be foretold, 

 from any of its predecessors." 



The discussion of temperature occupies 148 

 pages, with 44 tables and 30 figures. Nowhere 

 is there given an equivalent value in Absolute 

 or Centigrade degrees. The mean annual 

 temperature determined from doubtful records 

 dating back to 1830, is 282° A. (48° F.), 

 which does not differ greatly from the mean 

 obtained from the official records, 1871-1910. 

 The latter, however, are of somewhat doubtful 

 value since they were made at no less than 

 seven different localities. The table of daily 

 normal temperatures on page 33 leads us to 

 infer that the normals used by the Weather 



Bureau cover a period of 32 years only, while 

 data for 42 years are at hand. 



The highest temperature officially recorded 

 is 312° A. (103° F.), and the lowest 242° A. 

 (—23° F.). The year 1911 was the warmest 

 since the establishment of the office, if we 

 accept the Federal Building records without 

 correction. On 22 days the temperature 

 reached or exceeded 305° A. (90° F.). This 

 record was equaled in 1913. The greatest 

 daily range was 290°-261° A. (62°-10° F.) 

 which actually occurred between the hours of 

 eight A.M. and midnight. 



In discussing the effect of winds from Lake 

 Michigan it is stated " the specific heat of air 

 being less than one quarter that of water, the 

 interchange of heat will result in a larger 

 change of air temperature than of water tem- 

 perature." 



The meaning is not quite clear, but it should 

 be remembered that while the specific heat of 

 air (at constant pressure?) is 0.24, the specific 

 heat of water vapor is twice this, and it is 

 water vapor rather than air or water which is 

 the effective temperature control. The cooling 

 effect is noticeable at times far inland, but in 

 general decreases rapidly with distance, often 

 disappearing within 15 or 20 miles. The wind 

 records need not, however, be taken too seri- 

 ously, since the type of instrument used by 

 the Weather Bureau gives only eight points 

 of the compass, i. e., one direction covers 45 

 degrees. A shift of 22 degrees could not be 

 detected. Again, the elevations have been 

 changed a number of times, making the 

 velocities uncertain. Calculated on the basis 

 of hourly frequency, northeast is the pre- 

 vailing wind. The highest daily wind, 2,16Y 

 kilometers (1,347 miles), occurred at the Audi- 

 torium Tower, but the highest recorded at the 

 present location is only 70 per cent, of this. 

 The authors think that the present velocities 

 should be increased 10 per cent, to be com- 

 parable. 



The precipitation records likewise are open 

 to criticism, owing to faulty exposures and 

 frequent changes. The authors frankly state 

 that the effect of the poor conditions at the 

 Auditorium Tower can not be questioned. 



