30 



PROCEEDINGS OF THE AMERICAN ACADEMY 



Martha's Vineyard. On Vineyard Sound and on the island the storm 

 was severe. At Cottage City, on the island, the storm-clouds were 

 seen in the distant north at 12''.30, when the storm was forming, 

 seventy or eighty miles away. 



July 27, 28. The passage of another area of high pressure again 

 brouo-ht fair weather, with only two reports of thunder on the latter 

 date. 



July 29. (Fig. 3.) During the previous day the baric gradients 

 were very gentle, and our temperatures were high (mean max. 84°). 

 On this morning a slight baric depression lay north of Quebec, and 

 still maintained warm weather under its southwesterly winds (mean 

 max. 82°). Five separate storms have been traced for this day, the 

 charting being done by Mr. Clayton. 



a. The first one came early in the morning, being reported in 

 northern Vermont at 2 A. m., and reaching eastern New Hampshire 

 about eight o'clock, having travelled over a narrow path to the east- 

 southeast at a rate of perhaps eighteen miles an hour : it does not 

 seem to have reached the sea-coast. 



Fig. 3. 



h. The second storm advanced eastward along the boundary of 

 New Hampshire and Massachusetts, at a rate that may be estimated 

 at twenty miles an hour, and passed out to sea at noon. 



c. The third storm developed in northeastern Massachusetts about 

 noon, and moved eastward at the same leisurely rate as its predecessors. 

 Its rain-fall is recorded as over half an inch at several stations; its clouds 

 were dark and heavy, and several lightning strokes are reported ; but 



