One of our daily papers thus describes a method of car ventilation lately introduced on the Buffalo and New York Railroad, which is the invention of Dr. Foot, of Buffalo : a In the centre of the car there is a box about iour feet high, by two feet and two and a half in its dimensions. In this revolves a fan wheel, on the circumference ot which are teeth about half an inch long. This wheel moves in water to the depth of the teeth, and of course keeps a thick spray in the box when the car is in motion. The wheel is driven by a belt which connects with the car-axle. The air is sucked into the box at each side by the motion of the ian, which forces it through the spray into a conductor, which connects in several places with the car by means of ventilators, but in its passage through the spray it loses its dust and comes up pure. The car windows are to be shut in very dusty weather, and the air for breathing, pure and cool, passed through water, is to be thus furnished. The press of air made by the (an is so great that it will hold a hat suspended over one of the holes out of the top of the car. The experiment was successful to such a de-giee that it ought to be examined by competent judges.J; [This plan strongly resembles one described on page 340, Vol. 7, Scientific American, invented by Harvey Law, of thn city. The description to which we rerer says: "Mr. Law remedies the evil ol dust entering the cars by bringing the air in contact with revolving moist surfaces in troughs below the cars, and they take up all the sand and dust out of the air which is alterwards driven through the cars cool and pure." The idea ot extracting the dust from the air to supply railroad cars by drawing it through the water, belo; gs to Mr. Law, although the same principle was patented to James Cummings in 1S4S, as applied to Spark Arresters. ANOTHER CAR VENTILATORAnother mode of car ventilation has been introduced on the Naugatuck Railroad, Conn., by Messrs. At-woad Waterbury. The passenger cars of a train are all thrown into one long saloon by means ol a flexible cloth or rubber platform, and, the windows being kept closed and the train opened at the rear, a strong current ot air is received just over the engine through a pipe or bag, as wide as the train, and some six to twelve inches deep, which passes in at the top of the front car, and so along through all the cars, and out at the rear.