432 



Eighth Annual Report of the 



The low temperatures recorded in May are attributed to the 

 melting of ice in Lake Erie, Professor Dewey f^tating that the 

 lake frequently is mot clear of ice until about the middle of the 

 mouth. " Owing to its shallowness, Lake Erie is frozen over to 

 a large extent nearly every winter from December to March or 

 April, whereas the main body of Lake Ontario is sufficiently free 

 from ice to permit navigation even in the severest seasons." 



Local southwesterly winds prevail throughout the year on the 

 southern shores of both lakes and over much of the territory 

 between them, a result due in part to the deflecting influence 

 of the hills of so uith western New York, as will be made ap- 

 parent by an inspeotion of the accompanying relief map. The 

 southerly component is especially prominent in summer, giving 

 lake winds at Buffalo anid land winds at Rochester, with a 

 slightly lower temperature at the former than at the latter 

 place. Thus, Buffalo may properly be selected to determine the 

 maximum thermal effect due to the Lower Lakes, and for this 

 purpose its monthly averages were analyzed by the method re- 

 ferred to in connection with the temiperatures at Block Island. 

 The results are given, together with those for St. Louis, as an 

 example of a comtinental climate; Oooperstown as equidistant 

 from the lakes and the ocean ; Block Island and the State for the 

 purpose of extending comparisons. 



Probably somewhat more than the difference in epoch here 

 shown between Buffalo anid Oooperstown may safely be attrib- 



*The cosine formula T=A„-t-A, cos. (x~r) is used here, t Value as given by Ferrel. $The 

 periodic formula for New York Stnte, from which the curve of plate 1 was constructed, is as 

 follows: Trr45. !t°+24.4° cos [t— (202° 56')1 +0.76° cos. [2t— (311° 30')] +0.45° cos. [3t— (50° 50')]. 

 The mean monthly temperatures for the State used were the averages of the values at 

 Humphrey, Cooperstown, Lowville (Regents' record). New York city, Albany, Plattsburgh, 

 Canton. Oswego and Ithaca. The mean annual temperature thug derived for the State is 0.5° 

 higher than that of Table 2. 



