OF WIRES FOR ELECTRICITY. 323 
to 6, and back from 6, 5, to 1, and finally without any interposition. Ta- 
king afterwards the average of observations ofthe same kind, the influence 
which the loss of the power of the magnet might have exercised has been 
thus entirely removed. The length of all the wires collectively was 
= 16 feet Engl. The experiments are stated in the following table: 
Angles of Deviation. 
Without any wire interposed ... | 90°7| 93°6| 94°9] 95°3) 93°62 
16 feet of wire No. 1 interposed | 64°2) 66°3| 67:0! 67°4| 66°22 
No. 6 ————— | 55:0} 57:1) 57-9) 58°5| 57°12 
No. 449) 47-4) 4:°7°6] 48°6| 46:97 
—_——— | 29°6} 31°5] 31-2) 32°0| 31:07 
19:0} 19°8| 19°6| 19°7| 19°52 
9°3| 11°4! 10°8] 11°5| 10°75 
9°6| 11-6} 11-0} 11°7| 10:97 
18°1) 20°3| 19°0} 20°2| 19°40 
29°4| 31:5] 31-3} 31°8} 31°00 
45°2) 4°7°5| 48°0| 48°6| 47°32 
55°4| 55°3| 58:0) 57°3| 56°75 
649] 65°4| 67°0| 67°7| 66°25 
91-3) 91-9] 93°6| 94°7| 92°87 
Taking the average of observations made in similar circumstances, 
the values will be 
Angles of Deviation 
Difference. 
observed. | calculated. 
Without any wire interposed 93-24. 91°53 
With the wire No. 1 66°24 65°84 
aes No. 6 56°94 57°52 
etd lee NG) Li] | 47:16 48°09 
a NOS 31:04 31°22 
— No. 24 19°46 19°78 
No. 30 10°86 10°56 
The calculation was performed in the following manner : 
Let the strength of the current when it passes through a wire of 
the’ length used in these experiments (that is to say 16 feet), and of 
such a thickness that 2 feet of it weigh 1 gramme, be = py (where y is 
an unknown quantity to be determined by the experiment) ; and let the 
length of the wire of the multiplier, together with the length of the 
electromotive spiral reduced to the same thickness as the wire be, = a. 
