194 
Lieut. Foster’s account of the 
(srd. ) Oscillating the plate in different arcs, with its plane 
a tangent to the magnetic sphere, after the manner of the 
balance wheel of a watch, caused considerable deviations of 
the needle. In this experiment also, quick vibrations produced 
the least effect. 
In Table I. the observations are given at length, in order 
to exhibit the peculiar effect, already noticed, arising from 
the order of succession in which the points o, 60, 120, &c. 
were in the first instance brought to coincide with the fixed 
mark. The second column shows this order, and the third 
column, the zero or reading of the north end of the needle 
when the plate was placed on the pin previous to rotation. 
