376 Rotary Multiplier, or Astatic Galvanometer. 
blown at one ‘instant from the barn towards the house ; here however 
there was an upward and gyral current; the house was raised with 
it, and almost immediately thrown out of the vortex by its immense 
centrifugal force. Lighter objects which were carried up with it, 
were retained in the whirl a long time, and were finally thrown in 
very various and even opposite directions. 
The preceding results as to the character of the wind’s motion, are 
very similar to those which marked the New Brunswick hurricane of 
1836. It is desirable that the leading features of every great hurri- 
cane should be faithfully recorded, that we may in time be enabled 
to decide whether the preceding characteristics pertain alike to all 
hurricanes ; or if otherwise, into how many classes they are to be 
divided. 
Art. XXIII.—Rotary Multiplier, or Astatic Galvanometer ; by 
Cuas. G. Paces, M. D. 
Fieures 1 and 2 represent two new pieces of galvanic appara- 
tus, completed in the beginning of September last. Fig. 1 repre- 
sents a rotary or astatic gal- Fig. 1. 
vanometer, with a single nee- _————_Z » 
dle. mis the multiplier, com- 
posed of a number of turns 
of insulated wire. At c, an 
open collar passes through the 
center of the wires, to pre- 
vent any friction against the 
stem supporting the bar mag- 
netns. The multiplier m is 
mounted for revolution on a 
slender shaft 6, and has the 
-ends of its wires soldered to 
semi-cylinders of silver at a, 
upon which the battery wires 
FTL | ss 
(iiMHAcaRoraTL 
FMM GRINSTEIN TUTTE ST Ten ster TET 
(ae eee 
COVED AAE THD CEA TNT AAs 
pn press with a slight spring. a 
The cylindrical segments are not correctly represented in the pa 
Their relation to the battery wires should be such that the direction 
of the current should change when the coil of wire is at right angles 
to the magnet. The magnet being stationary may be very large 
