On page 235, this volume, SCIENTIFIC AMERICAN, we published a brief description of the success resulting from the employment of a steam fan in ventilating the coal mine at Abercarn colliery, England. In answer to this, we have received a communication from Stephen Cox, of Bridgeton, N. J., claiming priority of invention, and he has furnished us with some testimony to prove his title. He made a rotary fan, and put it to work in a mine at Reading? Pa., in September, 1854, and another for the same company in November following. Since then, it has been successfully at work, embracing a period of three years and seven months. The mine in which it is placed is three hundred feet deep, and the workings are a considerable distance from the shaft The fan is three feet in diameter, has four blades, and runs at the rate of twelve hundred revolutions per minute. A branch pipe from each inlet of the fan case connects with a main pipe, which is carried down tie shaft and into the rooms where the miners are working. Through this pips the foul air is sucked up, thus causing a current of fresh air to rush down the shaft and through the mine to supply the place of that which is exhausted. This fan is driven by the usual mine engine, and is not set in a separate ventilating shaft like the one in England. As it appears to be competent to fulfill ths offices for which it was constructed and arranged, it is an important fact for miners, inasmuch as it presents a very simple method of mine ventilation. In regard to its utility, Thomas Robarts, mine agent for Reeves, Buck & Co., of Phoenixville, Pa., states that the mine to which it has been applied, was previously almost impossible to work on account of foul air, but this was removed within an hour after the fan was set in motion, and the mine thoroughly ventilated. This is pretty high testimony to its efficiency. " Honor to whom honor is due."