10 Proceedings of the Royal Society 
Having seen such effects produced by imperfect means, we feel as 
if we had introduced our poor workman or needle- worn an from a 
dungeon into a summer-house, where the aged can read their 
Bible, — where the inmates can see each other, and carry on their 
work in facility and comfort. By pushing out the window we 
have increased by a few cubic feet the quantity of air to be 
breathed, and we have enabled the housemaid to look into dark 
corners where there had hitherto nestled all the elements of cor- 
ruption. To these inmates the winter twilight has been shortened, 
the sun has risen sooner and set later, and the midnight lamp is no 
longer lighted when all nature is smiling with the blessed influences 
of day. 
But it is not merely to the poor man’s home that these processes 
are applicable. In all great towns, where neither houses nor palaces 
can be insulated, there are almost in every edifice dark and gloomy 
crypts thirsting for light ; and in the city of London there are 
places of business where the light of day never enters, and where 
the precious light which the sky sends down between chimney tops 
is allowed to fall useless on the ground. On visiting a friend 
whose duty confined him to his desk during the official part of the 
day, we found him with bleared eyes struggling against the feeble 
light which the opposite wall threw into his window. We coun- 
selled him to extend a blind of fine white muslin on the outside of 
his window and flush with the wall. The experiment was soon 
made. The light of the sky above was caught by the fibres of the 
linen, and thrown straight upon his writing table, as if it had been 
reflected from an equal surface of ground glass. We may mention 
another case equally illustrative of our process. A party visiting 
the mausoleum of a Scottish nobleman wished to see the gilded 
receptacles of the dead which occupied its interior. There was 
only one small window through which the light entered, but it did 
not fall upon the objects to be examined. Upon stretching a 
muslin handkerchief from its four corners, it threw such a quantity 
of light into the crypt as to display fully its contents. 
But while our method of illuminating dark apartments is a 
great utilitarian agent, it is also an sesthetical power of some 
value, enabling the architect to give the full effect of his design 
to the external facade of his building, without exhibiting to the 
