256 



SCIENCE. 



[Vol. VII., No. 163 



on the 13th, viz., 2,000,000,000 gallons in twenty- 

 four hours, on seventy-eight square miles of 

 watershed. We have no records showing a 

 greater amount : the nearest approach was March 

 26, 1876, when the freshet was nearly as great." 



The form of precipitation was almost wmolly 

 rain, a little snow or hail having occurred at its 

 beginning at a few places only. The rainfall was 

 nearly continuous for about two days and a half, 

 but was not of equal severity. Indeed, the 

 greater part of the fall occurred in twenty-four 

 hours, as is indicated by the following table, 

 which contains the times of beginning and end- 

 ing of the rain, the total amount, and the amount 

 during a specified interval of twenty-four hours. 

 Similar records could be given from many other 

 stations. 



were duly chronicled by the daily press ; but it is 

 worthy of note, that, from the geographical posi- 

 tion of the flooded region, the damage was con- 

 fined to a relatively small area. The rivers were 

 affected only near their mouths, while a similar 

 rainfall in the northern portion of New England 

 would have caused wide-spread destruction. 



The meteorological records of former years have 

 been consulted for similar instances of excessive 

 rainfall. At Providence, which is in the area of 

 maximum rainfall, there are continuous records 

 since 1832, kept until 1876 by the late Eev. Dr. Cas- 

 well, and since that time by the city engineer. 

 There is no instance on record of a rainfall of 

 eight inches, though one exceeding seven inches 

 was noted in July, 1834 ; and during the week 

 March 20-26, 1876, the amount of 7.66 inches 









■a* 



<A v- 



Interval of 24 hours during heaviest 



Rainfall 



Station. 



Time of beginning. 



Time of ending. 





in 









*J 



rainfall. 



24 hours. 









Inches. 





Inches. 



New York 



11th, 10.30 a.m. 



13th, noon 



3.41 



11th, 11. CO a.m. to 12th, 11.00 a.m. 



2.99 



New London 



11th, 6.00 a.m. 



13th, 4.20 p.m. 



8.93 



11th, 11. CO p.m. " 12th, 11.00 p.m. 



6.66 





11th, 1.00 A.M. 



13th, 11.30 p.m. 



8.13 



12th, 7.03 a.m. "13th, 7.00 a.m. 



5.65 





11th, 7.45 a.m. 



13th, 2.45 p.m. 



5.62 



11th, 11.00 p.m. 12th, 11. CO p.m. 



4.45 





10th, 5-30 p.m. 



13th, 10.33 p.m. 



4.78 



11th, 9.00 p.m. " 12th, 9. CO p.m. 



3.30 



The immense amount of water which thus fell 

 in a few hours was of itself amply sufficient to 

 cause disastrous freshets, but it was largely aug- 

 mented by the snow and ice on the ground. The 

 depth of the snow at the beginning of the rain 

 lias been variously estimated. In a few places 

 there was none on the ground, but in the greater 

 part of the region it was found to a depth of from 

 two to fifteen inches. This was wholly melted, 

 and added to the rain as it forced its way over the 

 frozen ground to the rivers. The amount thus 

 added can only be conjectured ; for the snow was 

 in many places quite compact, and at the ground 

 there was a thick layer of ice. Several persons 

 have independently estimated that the equivalent 

 of two inches of water was obtained from the 

 snow and ice. This estimate is not excessive, and 

 may be adopted for the region where the rainfall 

 was greatest. 



An amount of water, therefore, exceeding ten 

 inches in depth in the maximum area, sought the 

 streams and caused their overflow, with disastrous 

 results. No attempt need be made to estimate the 

 damage to railways, public highways, manufac- 

 tories, and private property, the details of which 



was recorded. It is probably safe to say that 

 in Ehode Island no rainfall has been hereto- 

 fore recorded of so large amount in a single 

 storm, but there may be records of equally severe 

 storms in other parts of New England ; and one 

 which occurred in Connecticut Oct. 3 and 4, 1869, 

 was still more severe. 1 In this storm there were 

 reported at Hartford 8.43, Colebrook 8.44, Middle- 

 town 9.37, and Canton 12.35 inches. 



The following table contains the total amounts 

 recorded by observers who have kindly responded 

 to the request for their observations. The accom- 

 panying map contains the lines of equal rainfall 

 drawn from the observations. The numbers upon 

 the map correspond with those of the several sta- 

 tions in the table. It was found impracticable to 

 print the amount of rainfall at each station on ac- 

 count of the small size of the map. The lines 

 have been drawn freely, and do not follow closely 

 every individual record. In charting rainfall 

 records, which depend so largely upon the loca- 

 tion of gauges and the local topography, this is 

 impossible ; but it will be seen, from a comparison 



1 See paper by James B. Francis, C.E., in Transactions 

 of the American society of engineers, August, 1878. 



