32 PROCEEDINGS OF THE AMERICAN ACADEMY 



lation. Through the afternoon, showers of local formation began at a 

 number of places over New England, and moved about without coales- 

 cing into any general storm. Their distribution seems to have been more 

 detailed than that of our observers, so that it is quite impossible to follow 

 their tracks. The rain was seldom heavy, but when so, there seems to 

 have been a wind of more or less strength caused by it, blowing away 

 from the storm ; in such cases, the breeze was often felt at points be- 

 yond the area of the heavy rain. No definite statement can be made 

 as to the direction or rate of the storms' motion, but a number of ob- 

 servers speak of the cloud velocity as slow, and record the direction as 

 W. to E., or N.W. to S. E. A marked peculiarity of the day was 

 the severity of the lightning and thunder with but moderate rain-fall, 

 and the extension of the area where thunder was heard twenty or 

 thirty miles southeast of the margin of the rain area. 



Auw. 1 had an even more equable distribution of pressure than the 

 previous day, and its maximum temperatures averaged again 85°. 

 Thunder-storms developed about noon, and from 16^ to 18'' a large 

 storm of much severity was felt in central and eastern Massachusetts. 

 The wind of the storm was generally light, but in central Massachu- 

 setts showed the outblowing squall. A newspaper report mentions 

 destructive wind (tornado ?) at Bernardston, Mass. The rain was very 

 heavy at many stations, hail fell at a few places, and twenty -five strokes 

 of lightning were reported, although attention was not given especially 

 to this question. The early motion of the storm cannot be satisfacto- 

 rily determined ; much time has been spent in attempting to analyze 

 the many records gathered, but without good success, on account of 

 the irregularity in the line of rain-front and the complicated suc- 

 cession of showers. After raining heavily between Worcester and 

 Boston, the storm moved southeast, with a velocity of twenty or thirty 

 miles an hour, decreasing in intensity as it approached the coast after 

 sunset. 



Aug. 2. A low pressure centre now appears in Illinois, moving 

 northeastward. Under the influence of its easterly winds, the tem- 

 perature fell ten degrees below that of the day before, and rain was 

 recorded at a number of points. Few thunder-storm reports were 

 received ; several from southern Rhode Island imply a small storm of 

 some severity, with heavy rain, moving eastward about noon. 



Aug. 3. The low pressure centre, still moving slowly to the north- 

 east, occupied this day in passing between Lakes Huron and Erie ; 

 in New England, the temperature was moderate (72'^), with east- 

 erly winds and rain ; very few stations reported any thunder. On 



