8 
Proceedings of the Royal Society 
of tallow, oil, or gas, thus inhaling from morning till midnight the 
offensive odours and polluted effluvia which are more or less the 
products of artificial illumination. 
It is in vain to expect that such evils, shortening and rendering 
miserable the life of man, can be removed by legislation or arbitrary 
power. In various great cities attempts are making to replace their 
densely congregated streets and dwellings by structures at once 
ornamental and salutary ; and Europe is now admiring that great 
renovation in a neighbouring metropolis, by which hundreds of 
streets and thousands of dwellings, once the seat of poverty and 
crime, are replaced by architectural combinations the most beauti- 
ful, and by hotels and palaces which vie with the finest edifices of 
Greek or of Koman art. 
These great improvements, however, are necessarily local and 
partial, and centuries must pass away before we can expect those 
revolutions in our domestic and city architecture under which the 
masses of the people will find a cheerful and well-lighted home. 
"We must, therefore, attack the evil as it exists, and call upon 
science to give us such a remedy as she can supply. 
There can be no doubt that science does possess such a remedy 
— a remedy, too, easily understood and easily applied. Like all 
other remedies, however, it has its limits, but within these limits 
the principles and methods which science dictates are unquestion- 
able and efficacious. 
With rare exceptions, apartments are lighted with vertical win- 
dows, which admit the light of the sun, either directly or when re- 
flected from the sky, or from adjacent surfaces. In narrow streets 
and lanes, the light which enters the window comes chiefly from 
a portion of the sky, and the value of this portion as an illuminat- 
ing agent depends on its magnitude or area, and on its varying dis- 
tance from the sun in his daily path ; but whether the area be 
large or small, bright or obscure, it is the only source of light which 
the window can command ; and the problem which science pre- 
tends to solve is to throw into the dark apartment as much light as 
possible — all the light, indeed, which is visible from the window, 
excepting that which is necessarily lost in the process. 
In lanes or closes shut up at both ends by lofty houses, or by 
projecting buildings, it is sometimes only from a small portion of 
