150 Scientific Intelligence. 
candle at a distance of 230 centimeters. The luminous intensity 
of a cloudy sky was found at 10 a. m., one day also at York, to 
be such that light from it, through an aperture of one square 
inch area, is equal to about one candle. An experiment on sun- 
at o 
light, Glasgow, Friday, Dec. 8th, 2, showed ne o'clock 
that the sunlight was of such brilliancy that the amount of it 
coming through a pin-hole in a piece of paper of °09 of a centl- 
. . 
the corresponding area of the flame. This is 420 times the area 
of the pin-hole, and therefore the intensity of the light from the 
sun’s disc was equal to 126420 or 53,000 times that of a candle 
flame. his is more than three times the value found by Arago 
for the intensity of the light from the sun’s dise as compared with 
that from a candle flame.—iectrical Review, vol. xi, Dee. 2°, 
1882, p. 490. J. T. 
9. Dr. Siemen’s Address to the Society of Arts.—This address 
contains an interesting calculation of the cost of lighting large 
parish, constituting an aggregate of 2,926 horse power; nor dot 
this general estimate cover street lighting, and to light the six 
horse power per light represents a further requirement of 182 horse 
power, making a total of 3,108 horse power for purposes inde- 
pendent of house lighting, being equivalent to one horse power per 
inhabited house, and bringing the total requirements up to 109 
lights=twelve horse power per house. Assuming that the bulk 
ot domestic lighting remains to the companies, and that the 
electric light is introduced into private houses only at the rate of 
twelve incandescence lights per house, the Parish of St. James 
would have to be provided with electric energy sufficient to work 
63,378 lights=7,042 effective horse power; this is equal to about 
