Chapter 33 On the Effect of Taxes and of Legal Restrictions upon Manufactures 414. As soon as a tax is put upon any article, the ingenuity of those who make, and of those who use it, is directed to the means of evading as large a part of the tax as they can; and this may often be accomplished in ways which are perfectly fair and legal. An excise duty exists at present of 3d.(1*) per pound upon all writing paper. The effect of this impost is, that much of the paper which is employed, is made extremely thin, in order that the weight of a given number of sheets may be as small as possible. Soon after the first imposition of the tax upon windows, which depended upon their number, and not upon their size, new-built houses began to have fewer windows and those of larger dimensions than before. Staircases were lighted by extremely long windows, illuminating three or four flights of stairs. When the tax was increased, and the size of windows charged as single was limited, then still greater care was taken to have as few windows as possible, and internal lights became frequent. These internal lights in their turn became the subject of taxation; but it was easy to evade the discovery of them, and in the last Act of Parliament reducing the assessed taxes, they ceased to be chargeable. From the changes thus successively introduced in the number the forms, and the positions of the windows, a tolerable conjecture might, in some instances, be formed of the age of a house. 415. A tax on windows is exposed to objection on the double ground of its excluding air and light, and it is on both accounts injurious to health. The importance of light to the enjoyment of health is not perhaps sufficiently appreciated: in the cold and more variable climates, it is of still greater importance than in warmer countries.