Prof. Loomis on Electricity of Zine buried in the earth. 7 
when the galvanometer settled at 403°. In this experiment the 
three pairs of plates did not furnish the same intensity as two 
pairs in Exp. 34. By bringing the plates a little closer together 
some increase of effect would have been obtained; but although 
the experiment was several times repeated, nearly the same ad- 
vantage appeared to be lost in 5 ripen ag by the separation of 
the second copper plate from the first zinc, as was gained by the 
interposition of the third pair of sateas 
Exp. 36. I took three pairs of plates six inches by seven, all 
well secured at distances of one-third of an inch from each other, 
The outer copper plate was connected by a wire with the zinc 
plate buried in the earth, as in Exp. 30. The outer zinc plate 
was connected with the copper plate buried one inch from the 
zine, as in Exp. 31. pon lowering the battery into the well the 
galvanometer stood at 62°. 
Exp. I removed one pair of plates from the battery, the 
interval between the remaining ones being still one-third of an 
pee when the galvanometer stood at 6029. 
. 38. I removed a second pair of plates from the hattery, 
eiot only one pair separated by a distance of one-third of an 
inch in the well; and one pair separated by an inch buried in 
the earth, when the galvanometer stood at 
Thus it appears that one pair of plates immersed i in the vey 
fer ; 
affords a stronger current than two or three pairs. ‘The di f 
betyee — and three pairs is altogether trifling. 
Exp. 39. I removed the copper plate from 1 prouhll aiid the 
zinc ine from the well, when the galvanometer settled at 53°, 
The tangents of 53° and 70° are almost exactly as one to two, 
This experiment therefore ia ) the same conclusion as Exp. 
34, that with one pair o mits buried in the earth and one 
immersed in the well, t tensity of the current is double of 
that furnished by a sin air. 
Exp. 40-54. The following experiments were made to de- 
termine the influ of the size of the zine plate upon the in- 
WI I buried a plate of sheet zinc twelve 
spot employed in Exp. A plate of 
} hes by fourteen was attached to a wire and im- 
mersed in ell. Upon connecting the two plates by a wire 
the galva ster stood at 654°. I then er one-half of the 
the galvanometer stood at °. I continued 
» the zine plate and record i “Andiessions of the 
s. Column second shows the dimensions of the zinc plate 
: oye: column third shows the entire surface of zinc buried 
in the earth, counting both sides of the plate; column fourth 
_ shows the observed deviation of the galvanometer needle; and 
column fifth shews the natural tangent of the angle of deviation. 
