Accidents from the use of illuminating kerosene oil ought not always to be attributed to the impurity of the oil, or to the presence of the volatile explosive fluids that form a part of the composition of crude petroleum. There can be no doubt these frequently exist in oil that is sold as perfectly safe, and accounts of explosions of lamps are not infrequent. The law in relation to the purity of kerosene would, if rigidly enforced, prevent these disasters, but it is doubtful if an enforcement of the law is possible in all cases. But many kerosene accidents do not result from explosion, but from overturning or breaking the vessel, or lamp, and the ignition of the fluid, which is in all cases highly inflammable. A portion of this danger could, however, be removed by the employment of a perfectly safe lamp. Dr. Sanford, of Keokuk, Iowa, is satisfied that he has produced such a lamp, a representation of which is seen in Fig. 1, accompanying this article. His principle is to remove the flame to a safe distance from the oil reservoir, to make the latter of metal, and to feed the oil to the wick only in small quantities, as required. The lamp is simple does not require an engineer to run it easily kept in order, and gives a good light. The reservoir, A, is of polished metal, so as not to absorb the heat rapidly, and is closed by a screw cap. The wick tubes, B, are about three inches from the lamp, supported by braces, as seen; on the lower ones of which rest the pipes, C, which convey the oil to the wicks. The burners are of the usual form. The distance between the flame and the reser voir effectually prevents an j heating of the oil by conduction, and if the lamp should fall and break the pipes, the amount of escaping oil would be too little to produce any disastrous consequences. Fig. 2 is Dr. Sanf ord's plan for rendering the ordinary lamp safer. It is a hoop considerably larger than the lamp, to which is attached a series of buffers on its inside, made of rubber or other elastic substance, to protect the lamp from concussion. This guard is held in place by the cap of the lamp being screwed down upon it. The guard may be made as ornamental as desired. Fig. 3 is a vertical section of the wick tube and its accompaniments. The tube proper, A, is flat, as are the tubes, B, in Fig. 1. It is inclosed in a cylindrical tube, B, and projects through it at each end. Both are closed at the bottom except the small passage, C, leading from the wick tube to the oil in the lamp. The top of the round tube, B, is the screw cap of the lamp. Between the wick tube and its outer cylindrical sheath, is interposed, near the top, a gland, D, of some material not a conductor of heat, and the rest of the space between the tubes contains a fluid, which, if the lamp is overturned, flows out and extinguishes the flame if the oil should ignite. These inventions are both covered by letters patent. For further information address J. F. Sanf ord, at Keokuk, Iowa. _----- . ^^ - - Improved Adjustable-Reach Velocipede Undoubtedly the fewer the mechanical appliances interposed between the power and the proposed result the force exerted and the force delivered the more satisfactory will be product of the two elements. This theory is specially applicable to the velocipede. Four-wheeled vehicles propelled by the physical power of the rider are old ; the three-wheeled carriage is more modern ; the two-wheeled vehicle, now so popular, may perhaps be compelled to make way for the one-wheeled contrivance; and surely this latter is bringing the theory of wheel-riding to its ultimate perhaps carrying it beyond its proper limit. The machine shown in the accompanying engraving is, in effect, a unicycle, the small following wheel being only one point of suspension for the reach, and acting only as a truck or friction wheel. The driving wheel, which is also the steering wheel, may be of very great diameter, as it is worked, not by direct connection of the feet with the treadles, but by the hands and feet both, through the medium of connecting rods between the cranks and a walking beam. The reach supporting the seat is hinged to the lower end of an upright pivot secured in a yoke at the top of the forked brace,the lower end of which are boxes for the reception of the ends of the driving-wheel axle. This arrangement allows the wheel to be guided to the right or left, and also to be projected under the seat of the rider, or further in front. By this arrangement, when great speed is desired and the state of the road will permit, the rider may bring the wheel directly under him, and in descending grades he can project it in front to guard against the danger of being thrown over. In order to secure the wheel in either of these, or any intermediate position, a sector, notched on its upper side, and forming a portion of the reach, passes through a slot in the yoke, and a spring catch fits into the notches to hold the wheel and reach in the relation desired. The inventor claims as advantages over the ordinary two-wheeled vehicle, that it is easier balanced, when in motion, can be propelled at a higher rate rate of speed with the same amount of exertion, and can be driven over any ordinary road passable for other vehicles. Patent now pending through the Scientific American Patent Agency. Further information may be obtained by addressing the inventor, L. H. Soule, Mt. Morris, N. Y. m mm m Prof. Alonzo Jackman, of the Norwich University, Vermont, claims that he originated the idea of an ocean telegraph. In proof of this he republishes an article from his pen, published in the Vermont Mercwy in 1846. New Method of Working Ships' Rudders, A correspondent of the London Engineer furnishes that journal with the following, which we transfer to our columns : " I beg herewith to bring to your notice a new kind of rudder for seagoing vessels, or rather a new method for working the rudder. With the common rudder the greater the angle of divergence from the line of the keel the more power is required to bring the rudder into that position. With large vessels this power is something enormous, and we have lately seen in the letters from Mr. Reed that the rudder of the Minotaur requires the united exertions o f seventy-eight men to put it hard over when at full speed. To avoid this the balanced rudder has been used, and with evident advantage as regards the reduction of power required to work it. But the balanced rudder and its post have to stand considerably more strain and stress than the common rudder, inasmuch as the full force of the waves is exerted against a nearly unyield ing surface held in position by the upper bearing and the lower footstep. This latter is generally carried either by a projecting spur or on a framing securely fitted to the stern, and naturally throws great strain on the latter, is liable to being damaged, and awkward to get at. In fact the lower footstep has always been the stumbling-block against the application of the balanced rudder, which otherwise would, no doubt, long sincehave been more generally adopted. My improved rudder, as shown in the accompanying tracing, is designed to combine the advantages of both the common and the balanced rudder without their attending drawbacks. "The rudder is suspended from-the stern-post in any of the ways usual with the common rudder, but it has no rudder-post or spindle. A little behind the hinge, at a distance varying with the size of the rudder, an upright shaft or spindle is fixed, reaching to within a little of the rudder-blade, and carrying at its lower end a strong crank arm or lever with a pin provided at its outer extremity. The upright spindle is supported by a strong bearing near the crank, the upper end being connected to suitable steering gear. At the upper edge of the rudder a groove is provided, in which the crank pin can he made to slide. As the spindle is turned to the right or left, the rudder follows the movement of the crank to a less degreex diminishing in amount as the angle of divergence increases, until, when the rudder is hard over, the crank in plan stands nearly at right angles to the direction of the rudder. By this arrangement the leverage of the strain transmitted through the crank arm from the rudder to the steering gear is reduced as the angle of the rudder with the line of keel increases, and the dimensions may be chosen in such a manner as to cause very little variation in the strain on the gearing during manipulation. In my sketch the rudder is shown making an angle of 45 deg. with the keel, and in practice the crank will be placed so as to allow the rudder to swing back into its original position when released. This way of working the rudder has also the eminent advantage of being easily fitted to existing vessels, in which case the rudder-post may be retained as a provision against accident. I need hardly add that the arrangement shown in | my sketch represents only one out of a great many varieties in detail which may be adopted to suit circumstances. If you consider the foregoing sufficiently novel to merit your attention, I shall be obliged by insertion in- your next issue, for which please accept my thanks in advance." London. Joseph Bebnays. M. Fbiedel has just discovered that siliciureted hydrogen gas is entirely decomposed by the electric spark, giving rise in the eudiometer to a shower of a brown amphorous silicium.