TO PREVENT RAILWAY COLLISIONS.—Our attention has been directed to some editorial remarks in the " Norfolk Daily News," (Va.) relating to an invention of Dr. T. G. Clayton, of that place, lor the prevention of railway collisions. The invention is thus described : " When two opposing trains are on a track, one is to operate signals at suitable distance apart, to warn the other of approaching danger. A bent lever at right angles to the rail, is placed a.t suitable distances, say every two miles. This lever, acted on by the weight ol the cars, raises two signals at the distance ot one and two miles ahead, which are so contrived that the train on passsing the last signal, de presses the two, before it strikes the second lever. The levers only act in one direction: cars coming from the opposite direction pass over it without effect on the signals." It is stated by the " News " that it is to be tried on the Seaboard and Roanoke Railroad, and that the expense will not be more than $35 per mile. We hail every invention which has for its object the benefit of our fel low men. Every addition to the safety of railroad travelling enhances the value of rail road stock, for it secures an additional plea sure in the minds of travellers by the increas ed confidence of their safety. We have, how ever, always advocated double tracks as the sure and certain remedy lor railroad collisions, for we believe it is the only one in which we can place perfect reliance. We have seen a model of an invention for preventing railroad collisions by one train being made to operate the engineer's bell of the other, at a mile or two miles distant. ELECTRICAL PHENOMENON—Two weeks ago page 248, we copied a few remarks from the " Philadelphia Ledger," respecting some experiments which had been made in that city by Dr. Swaim, wherein a mode of light ing gas with the finger was described, viz., by obtaining a charge of electricity from belts for driving machinery. Dr. Swaim was in this city last week, and we had the pleasure of igniting gas with the tip of our finger, by simply walking across a carpeted floor, with a shuffling gait and pointing the finger at the gas pipe. The room in which the experi ment was made, was warm, the air dry, and the floor covered with a thick'Biussels car pet. The same results cannot be obtained unless the air is dry and the carpet isolated. Large sparks were obtained by pointing to a brass knob, by simply walking across the floor. Many of our readers will remember that on page 394, Vol. 5, Scientific American, we published the remarks of Prof. Loomis, of this city, which were made at the meeting of the American Association for the Advance ment of Science, held at New Haven in 1850. He stated that to his knowledge there were certain electric houses in New York city, in which a stranger upon entering and attempt ing to shake hands, received an electric shock. He had tried and witnessed the same phenomenon as Dr. , Swaim by walking across a carpeted floor, except igniting the gas. On the page referred to we mentioned the case of a carpet being set on fire by electri city generated in the same manner. We have much to learn yet respecting electrical phe nomena. SETTLEMENT OP A GREAT PATENT CASE.— The case of Sloat vs. Patton, in Philadelphia-, in which an injunction was granted has been settled. The complainant having purchased out Mr. Patton's interest for $25,000. A jury trial had been ordered by Mr. Jus tice Grier, which was set down at the present term, to test the question of infringement on the Woodworth patent. NEW STEAM YACHT.—Cornelius Vanderbilt, Esq., the wealthy steamship proprietor, is having a beautiful steam yacht constructed, named the " North Star." The engines are now being put in at the Allaire Works ; they are double overhead beams with cylinders of 60 inch diameter and 10 feet stroke. It is re ported that Mr. V. will take a personal trip in her to Europe, along with some friends, during the coming summer. We hope he will, so as to test the beam in comparison with the side lever engines on the Atlantic.