OP ARTS AND SCIENCES. 49 



especially evident in a fast moving storm like this one, where the ve- 

 locity was almost a mile in a minute : an inaccuracy of ten, or even of 

 five minutes, would cause a considerable error in drawing the storm- 

 front curve. The incompleteness of records is especially to be regret- 

 ted; for example, at Springfield two observers failed to make any 

 report, and the brief statement for that station is taken from the regu- 

 lar record of the observer of rain-fall, who reports for our monthly Bul- 

 letin. Hartford makes no mention of the storm, although it must have 

 passed within sight, if not within ear-shot. A number of stations in 

 central Rhode Island were also silent. Besides this, the occurrence of 

 considerable stretches of country from which we have no records is 

 especially unfortunate. Although the number of reports is consider- 

 able, there are certain districts where they are lamentably insufficient, 

 and, in constructing the maps to illustrate this storm, one has contin- 

 ually to regret the lack of observers in numerous good-sized towns 

 situated directly in the path of the squall. 



Figure 5 represents the path and progress of this storm, as deter- 

 mined by charting all the observations collected. Stations where rain 

 was noted are marked by a black dot. The curved dotted lines show 

 the supposed attitude of the rain-front for every quarter-hour. Arrows 

 indicate the velocity and direction of wind accompanying the rain. A 

 number of valuable negative records, such as "no rain " or " distant 

 thunder " while the storm was passing, are represented by small circles, 

 with T on the side from which thunder was heard. As thus deter- 

 mined, the average velocity of the storm's progress is forty-eight miles 

 an hour ; its path lay a little south of east ; it seems to have run faster 

 in eastern Connecticut, and on entering southeastern Massachusetts it 

 suddenly extended to the northeast. Besides the larger storm of the 

 afternoon, three others were observed on the morning of this day ; one in 

 southeastern New Hampshire and northeastern Massachusetts ; another 

 to the southeast of Boston, which may have united with the principal 

 squall out at sea ; but while on land they were distinct, as is proved 

 by the three " no rain " stations between them ; the third was a small 

 storm in southern Rhode Island, about 13.00 to 14.00 hours. Return- 

 ing again to the chief storm of the morning, we find that in south- 

 eastern Massachusetts the scanty time records do not suffice to define 

 the storm-front, which there seems to become irregular ; but elsewhere 

 the storm was strongly convex to the east, with its most violent action 

 in rain, wind, and lightning at the apex of the curve. All observers 

 agree that the storm came and passed away quickly ; the rain-fall sel- 

 dom measured over a quarter of an inch, but the fall was often heavy 



VOL. XXII. (n. S. XIV.) 4 



