Leather suffers greatly from heat and damp; but, like timber, more especially when subjected to alternations of heat and moisture. Toughness and tenacity are the chief qualities required for leather for carriages, and these qualities depend chiefly on the presence of a certain quantity of oil or fatty matter which the leather imbibes like a sponge. On this matter the oxygen of the air acts strongly, and at length consumes it; and if it be not renewed the leather cracks. If the leather be exposed to wet and damp this process is more rapid, but when the leather is frequently oiled it is apt to look dull and occasion much trouble to the coachman, who most likely will prefer blacking it, but the materials of which blacking is composed tend to the decomposition and destruction of the leather. Leather which is painted or japanned possesses little or no tenacity, and is never oiled. The patent grained elastic leather, which is so very much in use for hoods and knee-flaps, is a very beautiful substance to the eye, and is quite waterproof so long as it is free from cracks; but dryness and heat are liable to cause it to crack. Also, if one portion of the surface be kept in contact with another portion during warm weather, it is liable to stick and strip away when pulled apart. When it cracks and water gets in, it decays rapidly. Generally speaking, it is preferable to use oiled leather for heads, if ordinary care and attention be bestowed upon it; for though its durability is not so great, there is a saving of labour in keeping it tidy, and it has a very good appearance. The cloth, silk, and lace composing the lining, &c., and used in combination with wool, hair, cotton, and linen, suffer from the rays of the sun by losing their rich colours, and from the damp by becoming mildewed and rotten. Cloth, hair, and wool also suffer from another cause, viz. moths. In open carriages this is a very serious evil. Hammercloths are protected by a patent india-rubber cloth being put over them; cedar shavings also exercise a destructive influence on moths. The india-rubber cloth is as good as anything where the smell is not objected to, but this in warm weather is very strong and unpleasant. However, it would be a very good thing to introduce some cedar shavings in the stuffing of linings, and this might to some extent get rid of the troublesome pest.