142 proceedings: philosophical society of WASHINGTON 



States. (2) The prolonged period of high temperature over the 

 Plains States preceding the hot spell. (3) The absence of clouds and 

 consequently unhindered insolation throughout the period of the hot 

 weather. 



Diagrams were shown illustrating the pressure distribution in the 

 United States at the beginning of the hot spell and its daily eastward 

 advance to the Atlantic. 



The eastern limit of the hot weather corresponded roughly with the 

 72d meridian of west longitude, which it may be remembered passes 

 through central Massachusetts. 



Local thunder showers set in over the upper Ohio valley, the northern 

 portion of the Appalachian region, western Maryland, and the District 

 of Columbia in the later afternoon of the 7th, bringing to an end in those 

 districts the unusually high temperatures that had prevailed during 

 the preceding 48 hours. While high maxima were recorded in eastern 

 Pennsylvania, eastern New York, and western New England on the 

 yth, local showers on the 8th brought relief from the extremely high 

 maxima but normal temperatures were not reached in the east until 

 the 14th. 



Discussion: This paper was discussed by Messrs. White, Kimball, 

 Humphreys, Kadel, and Hayford. 



The 8ioth meeting, being the 48th annual meeting of the Society, 

 was held at the Administration Building, Carnegie Institution, Decem- 

 ber 7, 1 91 8; President Burgess in the chair; 22 members present. 



The report of the Secretaries was read by Mr. E. C. Crittenden. 

 This report showed that the present active membership is 182, a net 

 gain of 12 during the past year. Among the active members there 

 were seven deaths during the year, namely: Henry Adams, Thos. 

 B. Ford, G. K. Gilbert, R. A. Harris, Artemas Martin, Richard 

 Rathbun, Geo. M. vSearle. Also one member on the absent list. 

 Captain Ernest Weibel, died of wounds received in France. There 

 was one resignation during the year and thirteen were transferred to 

 the absent list, a number of these being men who were engaged in over- 

 seas military duty. There were 2i2> ^i^w members elected during the 

 year. 



The Society held 14 meetings for the presentation of papers. At 

 these meetings :^2) communications were presented. About 15 per 

 cent of the Society presented papers. The average attendance at the 

 meetings was 45, constituting about 25 per cent of the membership of 

 the Society. 



The General Committee adopted new By-laws on December 22, 191 7, 

 to supplement the revised By-laws of the Society which had been 

 adopted November 24, 191 7. These By-laws have been published 

 and issued to the members of the Society. 



The report of the Secretaries was accepted and ordered placed on 

 file. 



