me that the turret still acts very well, drying kip butts on the upper floor a good colour in all weathers in about a week. He finds, however, that the steam-pipes as described are hardly sufficient in very cold weather, and intends to increase them, or replace with 1300-1400 ft. of hot water pipe heated by a saddle boiler. At Lowlights tannery, a shed arranged on the turret principle (though much less completely carried out from want of height in the buildings) has been for many years in operation, principally for drying off sole-leather, with the most satisfactory results. [Illustration: Fig. 66.] It is noted by Box ('Practical Treatise on Heat,' p. 166) that an exit for the moist air should not be placed at the top of a drying-chamber, but at the bottom, since in the first case, the hot dry air tends to rise at once to the opening, and pass away unsaturated with moisture, while that cooled by evaporating water from the goods, being heavier, tends to form downward currents and remain in the chamber. To this it may be objected that aqueous vapour is much lighter than air; this is true, other things being equal, but in practice the evaporation of a given quantity of water cools the air and makes it heavier in a materially greater degree than the admixture of aqueous vapour lightens it. This source of waste of heat exists in the turret drier, but is there, from its great height, reduced to a minimum. In lower sheds it becomes very material, and the air currents formed are productive of much harm by causing irregular drying. This difficulty has been met by Mr. Edward Wilson, of Exeter, to whom the leather trade owes several very useful inventions, by an ingenious drying-room constructed on the lines indicated by Box, though I do not know that he was in any way indebted to that writer for the idea. In this Mr. Wilson arranges the steam-pipes, instead of on the floor, in a vertical compartment partitioned from the chamber, through which air is admitted and heated. This hot air fills the top of the chamber and from its lightness floats in a horizontal layer, only descending and escaping by apertures in the floor as it becomes cooled by evaporating the moisture of the hides. Mr. Wilson states that the method answers well in practice, and it is certainly the most scientific in conception, but it might be feared that, as applied to a single floor, the upper parts of the butts, suspended near the ceiling, would dry more rapidly than those near the floor. If applied to a double-floored building, this disadvantage would, from the stronger draught, and consequent larger supply of air, be less likely to show itself, and the upper floor with its uniform warm air would be well adapted for drying off finished sole-leather, while the cooler and milder drying of the ground floor would be fitted both in character and situation for that wet out of the yard. Special precaution would be needed to prevent the heated air escaping by doors