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.
(416.) The effects of regulations of excise upon our home manufactures are often productive of great inconvenience; and check, materially, the natural progress of improvement. It is frequently necessary, for the purposes of revenue, to oblige manufacturers to take out a license, and to compel them to work according to certain rules, and to make certain stated quantities at each operation. When these quantities are large, as in general they are, they deter manufacturers from making experiments, and thus impede improvements both in the mode of conducting the processes and in the introduction of new materials. Difficulties of this nature have occurred in experimenting upon glass for optical purposes; but in this case, permission has been obtained by fit persons to make experiments, without the interference of the excise. It ought, however, to be remembered, that such permission, if frequently or indiscriminately granted, might be abused: the greatest protection against such an abuse will be found, in bringing the
