Pratt's machine is worked by one or two horses, or by steam or water power, as is convenient. The price of the smaller size, worked by one horse, is $150, and the price of the larger size, worked by two horses, $200. Professor Mapes says he saw this machine in operation and considers it "perfect in all its parts." The patentees claim that they can make, with the one-horse machine, 5,000 large tiles a day. They state also that "two horses will make tiles about as cheap as bricks are usually made, and as fast, with the large-sized machine." [Illustration: Fig. 53.--PRATT'S TILE MACHINE.] These somewhat indefinite statements are all that we can give, at present, of the capacity of the machines. We should have no hesitation in ordering a Pratt machine were we desirous of entering into an extensive business of Tile-making, and we should feel quite safe with a Daines' machine for a more limited manufacture. SALISBURY'S TILE MACHINE. S. C. Salisbury, at the Novelty Works, in the city of New York, is manufacturing a machine for making tiles and bricks, which exhibits some new and peculiar features, worthy of attention by those who propose to purchase tile machines. Prof. Mapes expresses the confident opinion that this machine excels all others, in its capacity to form tiles with rapidity and economy. We have examined only a working model. It is claimed that the large size, with horse-power, will make 20,000 two-inch tiles per day, and the hand-power machine 3,000 per day. We advise tile makers to examine all these machines in operation, before purchasing either. CHAPTER X. THE COST OF DRAINAGE. Draining no more expensive than Fencing.--Engineering.--Guessing not accurate enough.--Slight Fall sufficient.--Instances.--Two Inches to One Thousand Feet.--Cost of Excavation and Filling.--Narrow Tools required.--Tables of Cubic contents of Drains.--Cost of Drains on our own Farm.--Cost of Tiles.--Weight and Freight of Tiles.--Cost of Outlets.--Cost of Collars.--Smaller Tiles used with Collars.--Number of Tiles to the Acre, with Tables.--Length of Tiles varies.--Number of Rods to the Acre at different Distances.--Final Estimate of Cost.--Comparative Cost of Tile-Drains and Stone-Drains. A prudent man, intending to execute a work, whether it be "to build a tower," or drain a field, "sitteth down first and counteth the cost, whether he hath sufficient to finish it." There is good sense and discretion in the inquisitiveness which suggests so often the inquiry, "How much does it cost to drain an acre?" or, "How much does it cost a rod to lay drains?" These questions cannot be answered so briefly as they are asked; yet much information can be given, which will aid one who will investigate the subject.