118 Scientific Intelligence. 
rapid evolution of heat, and the facts force upon us the conclusion, that 
the destruction of mechanical motion is the one and only efficient cause. 
ics, 
of motion is equally irresistible. Lastly, it is evident that the facts here 
stated perfectly accord with the well-known experiments of Rumford 
and Davy; only since the moving power of the Merrimack turbine is 
the Boston office of the nevi nine Telegraph Company lines, upon the 
magnetic effects of the au 
a wes that in in one case, the deflection of the needle of his 
I fouind it to reeenoue to thie ¢ evolution of 3883, of a cubic centimeter 
of mixed oxygen and hydrogen gases per minute, equal to the decompo- 
sition of 335 of a grain of water per hour. 
et us assume for the unit of strength of current the evolutions of 
one cubic centimeter of mixed gases per minute, and let S signi 
strength of current measured according to this unit. Let the unit of 
resistance be that offered by one foot of a round wire, one twentieth of 
an inch in diameter, and made of pure copper, (nearly = 13000 000 foot- 
seconds,) and let R denote units of resistance. Denote units of electro- 
motive force by E, then will E=RS. Furthermore, denote units of 
electrical energy by E, then will E=RS?=ES express the relations 
between electrical energy and its corresponding resistance, electromotive 
force and strength of current. The mechanical value (denoted by M) 
of this unit of ang energy is equal to yo4%sh40q foot-lbs. per minute, 
or M= 
he m pa resistance of the line from Boston to Springfield, in- 
cluding the relays in circuit, was found to be equal to 515970 of our 
units; hence the electrical energy per minute, exerted by the aurora 
upon the line while the needle stood at 78°, was E= 515970 X(‘683)?= 
241241; and its equivalent mechanical Patan was M—-0019 kK 241241=> 
46.178 foot-lbs. per minute. 
This wire is of iron, and is one hundred miles in length; it was orig: 
kd of the wire known as No. 9, hence its volume spnld not exceed 
i *yx (148)? 5280 X 12 KX 100=108925 cubic inches,—63°03 cubic feet. 
Therefore the mechanical energy me eubic foot of the wirex ot = 
7°32 foot-lbs. per minute. 
If we suppose the auroral energy to be equa’ uall: active at all points. of 
space where its presence was evident, we s find it to amount to 
