L04 Miscellaneous Intelligence. 



determine the exact form of the lakes, and further, a detailed state- 

 ment of the observations of the temperature of the water through 

 the different seasons of the year. The change of conditions from 

 the time when the lakes were covered with ice to the warmer 



period of the summer, and again to their freezing in winter, lias 

 been traced out with great minuteness, and the results, while not 

 in all respects novel, contain several points of interest. It is 

 remarked, for example, that the warming of the surface water is 

 accomplished exclusively by the direct radiation and is almost 

 independent of the temperature of the air. The increase in sur- 

 face temperature may amount to as much as six degrees in a day, 

 though most of that is lost again during the night, particularly in 

 the case of clear weather. At a depth of four meters the effect of 

 the sun's rays may amount to as much as half a degree in a day, 

 while at ten or twelve meters a warming of only one or two 

 degrees in the course of the entire summer is noted ; but great 

 differences result according to the purity of the water. It was 

 found, further, that the freezing over begins when the temperature 

 has cooled down to + 1 or + 2, and a temperature of zero degrees 

 before freezing was never observed. It is remarked that further 

 investigations are needed to explain this anomaly. Attention is 

 called in this connection to a paper by Arnet on the freezing of 

 the lakes in Central Switzerland from 1890 to 1896, in which it is 

 stated, in regard to Lake Luzerne, that during freezing and while 

 ice covered the lake, no temperature below 1*25 C. was noted. 



2. Field Columbian Museum. — The following are recent publi- 

 cations : 



Publication 23, Anthropological Series, vol. ii, No. 2. A 

 Bibliography of the Anthropology of Peru ; by George A. 

 Dorsey; pp. 57-206. 



Publication 25, Botanical Series, vol. i, No. 4. Contribution 

 III to the Coastal and Plain Flora of Yucatan ; by Charles 

 Frederick Millspaugh ; pp. 345-410. 



Publication 26, Zoological Series, vol. i, No. 9. List of a 

 Collection of Shells from the Gulf of Aden, obtained by the 

 Museum's East African Expedition ; by Dr. W. II. Dall. D. G. 

 Elliot, Curator of Department; pp. 187-189. 



Publication 27, Zoological Series, vol. i, No. 10. Lists of 

 Species of Mammals, principally Rodents, obtained by W. VV. 

 Price, Dr. S. E. Meek, G. K. Cherrie, and E. S. Thompson, in the 

 States of Iowa, Wyoming, Montana, Idaho, Nevada, and Cali- 

 fornia, with Descriptions ol New Species ; by D. G. Elliot; pp. 

 193-221. 



The Pruning Book: A monograph of the Pruning and Draining of Plants as 

 applied to American conditions; by L. H. Bailey; 537 pp. New York, 1898. 

 (The Macmillan Company.) 



The Social Mind and Education. By George Kdgar Vincent. 155 pp. New 

 York and London, 1897. (The Macmillan Co.) 



