38 Mr. Redfield on the Rotary Action 
The superb instrument with which the above determina- 
tions were made, having been deposited for safety in the long 
Armoury at the Tower, was most unfortunately destroyed by 
the fire which consumed that part of the edifice in 1841. 
The volume concludes with the announcement that the 
triangulation for connecting all the stations by geodetical di- 
stances is in an advanced state, and will be given in a subse- 
quent publication. 
VIII. On the Evidence of a general Whirling Action in the 
Providence Tornado. By W.C. Reprierp, A.M.* 
ON the 30th of August, 1838, between the hours of 3 and 
4 p.m., a violent whirlwind or tornado visited the town 
of Providence, in the State of Rhode Island. It was preceded 
by a shower of rain of short duration, after which the tornado 
appeared, appended to another cloud, and passed through the 
southern part of the town nearly from west to east. 
Its earliest ravages reported, were in Johnston, at the farm 
of Mr. Randall, about seven miles west from Providence. 
From this point it passed on through Cranston and Provi- 
dence, where, crossing the river into the State of Massachu- 
setts, it passed through Seekonk, Rehoboth, Swansey, Somer- 
set, and as far, at least, as Freetown, beyond ‘Taunton river; 
a distance of twenty-five miles from the point first mentioned. 
The width of its visible track, as indicated by the prostra- 
tion of trees, fences, and other objects, varied from a mere 
trace in its narrowest, to two hundred yards or upwards in its 
widest portions. Having a few days after the occurrence of 
the tornado carefully examined the track for the distance of 
about seven miles, on each side of Providence river, I pro- 
pose to offer some of the results of this examination, together 
with such remarks as may seem justly deducible from the ef- 
fects observed. 
So far, however, as the impressions made on an accidental 
eye-witness of the tornado may be important, we have a valua- 
ble account furnished us in the letter of Zachariah Allen, Esq., 
of Providence, which is given in Dr. Hare’s notice of this tor- 
nado. [This (Silliman’s) Journal, vol. xxxvili. p. 74-77.] 
Mr. Allen had the advantage of viewing its progress from 
a point near its path. He calls it a “ whirlwind,” and de- 
scribes its phenomena in a manner perfectly consistent with 
this appellation. ‘ The circle formed by the tornado” on the 
river, he describes as “about three hundred feet in diameter,” 
* From Silliman’s American Journal of Science and Arts. 
