Page:Scientific Memoirs, Vol. 1 (1837).djvu/632

$\lambda \,\;=38.81$	therefore	$L+l+\lambda \,\;=712.06$,
$\lambda '\,=10.78$	———	$L+l+\lambda '\,=684.03$,
$\lambda ''=.\,5.44$	———	$L+l+\lambda ''=678.69$,

the equation (A.) gives therefore

$x\,\;=712.06\cdot p\cdot \sin .(19^{\circ }\,\,3'),$

$x'\,=684.04\cdot p\cdot \sin .(19\,\,48\,\,),$

$x''=678.69\cdot p\cdot \sin .(19\,\,51\,\,),$

or, if the two last electromotive powers be compared with the first, the proportions

${\frac {x}{x'}}={\frac {712.06\cdot \sin .(19^{\circ }3')}{684.03\cot \sin .(19^{\circ }48')}}=1.00305\quad {\mbox{and}}$

${\frac {x}{x''}}={\frac {712.06\cdot \sin .(19^{\circ }3')}{678.69\cdot \sin .(19^{\circ }51')}}=1.0085.$

Both propositions differ so little from unity that we are fully warranted in concluding that the electromotive power which the magnet produces in the wire No. 1 is quite as strong as those in the wires Nos. 3 and 4, although the latter possesses a diagonal almost four and seven times greater, and therefore that the electromotive power is independent of the thickness of the wires. A second confirmation of this position is found in the following experiment previously made:

		Angle of Deviation.				Mean.
		1	2	3	4
10 Conv. of wire	No. 3	36·3	37·8	33·5	35·7	35·82
—————	No. 2	36·0	37·0	32·1	34·9	34·0	34·95
		35·4	36·8	32·6	35·0	35·9
—————	No. 3	33·6	35·5	35·7	37·3	35·52

Consequently we have for

No. 2,	$\alpha .=34.95$,	further	$\lambda .=34.00,$	also	$L+l+\lambda .=707.25$
No. 3,	$\alpha '=35.67,$	———	$\lambda '=11.52,$	and	$L+l+\lambda '=684.77,$

consequently

${\frac {x}{x'}}={\frac {707.25\cdot \sin .(17^{\circ }.29')}{684.77\cdot \sin .(17^{\circ }.50')}}=1.013.$

Here also the proportion is so near to unity that we may from this, combined with the above results, regard it as an established truth, that

"the electromotive power produced in the spirals by the magnet remains the same for every thickness of the wires,or is independent of it."

From this law again it immediately follows that in rings of wires of various thickness surrounding the armature of the magnet, the electric