Many ingenious devices, some of them of practical utility, were to be seen at the seventh annual toy show at the Tuileries, Paris. Diabolo, the ancient game that has again become popular, was represented by numerous models, ranging in price from two cents to more than two dollars, according to size or material, the latter including wood, metal, celluloid, cork, rubber, and cloth. Diabolo has inspired several similar toys; among which is the "climbing shell." The apparatus consists of a deeply grooved flat spool or disk, a cord, and a fork with two bent tines. A metal pin projects from each side of the disk to hold it on the fork, One end of the cord is attached to the disk, the other held in the hand with the fork, and the cord is wound up in the groove. The pins are rested on the fork, when the latter is tilted to let the disk roll off. As it. falls it rapidly unwinds, and as it reaches the end of the cord keeps on spinning, and so rewinds itself up the cord. Just as the disk is at the lowest point a quick upward pull is given to the cord. This pull must be just sufficient to replace the energy lost by the disk, and so enable it to climb as high as the point it fell from. The trick consists in giving the right amount of jerk at the right moment, and to present the fork in such a way that the disk is caught at the top of its flight. Similar in principle to the foregoing is the Rail Ball. A rubber ball is placed on two parallel curved rails, one extremity of which is held in the hand, and the ball is caused to roll up the rails and lodge securely in the ring which terminates them, by means of a dexterous movement of the wrist. The rails and the ring are made of one piece of iron wire. The Joust is another game of skill. A little tub filled with water or flour swings from a cross-beam supported by two posts. One end of a railway is inserted between the heavy bases of the posts and the other end is supported on blocks at any desired height. In a carriage stands a puppet armed with a lance. It is required to adjust the direction and the inclination of the railway so that, when the carriage rolls down the grade, the lance shall enter a hole in a vertical plate attached to the bottom of the tub. Otherwise the lance will strike the plate and overturn the tub, spilling its contents on the lancer. The difficulty is increased by giving an oscillating motion to the lance. Similar jousts, entailing the same risk of being drenched with water or covered with flour, are practised by human lancers at French country fairs. The Weathercock Race is a modification of the popular French game of "Petits cheveux." The innovation consists in causing the circle of horses and riders to revolve, alternately in opposite direction, as it glides down a pole. This result is accomplished by means of two spiral grooves, corresponding to right and left handed screws of long pitch, which are cut on the inside of the sleeve or hub of the circle of riders, and which encounter and engage with pegs on the post as the circle descends. The horse which stops nearest a marked goal is the winner. Another game of chance is Toboggan Marbles or Toboggan Billiards. An inclined board is crossed obliquely by a number of wires. A small interval is left between the lower end of each wire and the upper side of the next one, so that a small ball, placed on the upper wire, will roll down along all the wires in succession, following a zigzag course, to the bottom of the board, and there fall into a numbered compartment. An interesting feature is the automatic and successive release of the twelve balls, which is accomplished as follows: A rod, mounted so that it can turn freely on its axis, runs along one inclined side of the board. The ends of this rod are bent in such a manner that, during the descent of the first ball, the second and succeeding balls are stopped by the upper bent end, but when the moving ball reaches the bottom of its course it lifts the lower bent end of the rod, thus releasing the second ball by turning the rod, which immediately falls back into its original position and holds the third and succeeding balls. Along the other inclined side of the board an endless band is stretched over two rollers. By turning a crank attached to the upper roller a sort of spoon carried by the band is made to pick up the balls from the receptacle at the base and carry them, one by one, to the top wire, for another descent. The Balloon Accident is a lottery in which the winner is determined by the fall of the aeronaut. A card 463 is divided into sectors marked with the names of different countries. From the center rises a mast which bears a yard at its top. An imitation balloon, with its basket and aeronaut, is hoisted by a cord which runs up the mast and over a pulley on the yard. But the pulling of the cord also causes the mast to rotate so that the balloon passes over the different countries. The contact of the top of the balloon with the yard releases one of the attachments of the basket which overturns and drops the aeronaut. The players guess the country in which he will land. The Triplane is a vehicle that can travel on land, on water, and through the air. It has a hull in the form of a double cone, and four wheels for traveling on land. It is propelled by a large air propeller, driven by clockwork, and develops a fair speed both on land and on water. For aerial navigation the wheels are replaced by aeroplanes and the vehicle is suspended by a long cord. The Triplane is an instructive toy, be-cause it illustrates the action of air propellers. Another scientific toy bears the fanciful name of Houille Blanche, or White Coal, which French writers apply to waterfalls regarded as sources of power. A small but powerful turbine, attached to a water tap, drives a variety of machines, including a little dynamo which produces sufficient current for the operation of a tiny incandescent lamp, thus giving a striking illustration of the transformation of energy. The Cord Telegraph comprises two grooved posts, two equal weights which slide in the grooves, and a long cord attached to the weights and passing over pulleys at the top of the posts. Each post is marked with the letters of the alphabet, but the alphabetical order runs up one post and down the other. Each weight carries a pointer. If one weight is moved so that the pointer indicates successively the letters of a word or cipher the other weight will move so as to spell out the same word on the other post. The posts may be set at any distance apart. The call is made by moving the weight rapidly to the bottom of the post, thus raising the other weight as rapidly to the top of the distant post, where it strikes a bell. The Cord Alphabet is an instructive puzzle designed to fix the forms of letters in the minds of young children. The apparatus consists of a pattern alphabet, a cord, and a board in which about forty nails have been driven in such arrangement that any of the capital letters and numerals can be made by wrapping the cord around the proper nails. Two devices of practical utility deserve mention. The Bath Screen, or Spray Catcher, is designed to supplement the ring douche and protect the carpet, which is likely to suffer if no screen is used, even if the tub is three feet in diameter. With the screen a small foot tub suffices and a bath can be taken in the smallest room. The screen is a bottomless bag of waterproof fabric, distended by a rigid ring at the top and supported by cords attached to a smaller ring which rests on the shoulders. The Electric Searchlight has a wide field of useful- ness. The battery is of the bottle type and its only novel feature is the ease with which it can be taken apart for cleaning. This is important, as cleanliness is essential to perfect working. The zinc, which is the only part consumed, can be renewed with the greatest ease. The lamp is mounted on a joint so that it can be turned in any direction. For use in the photographer's dark room the lamp and reflector can be inclosed in a hood with a ruby window. For reading in bed, a short focus lens, mounted in a similar manner, projects a strong parallel beam. If the zinc is immersed gradually the lamp may be used several hours.Translated for the SCIENTIFIC AMERICAN from La Nature. The Hand Grenade In Our Army. The Ordnance Department of the army has been experimenting for some time past with a hand grenade, for use in places where the attacking party has been able to come close to the besieged, and when the fire of the small-arms rifl-e would be ineffective, owing to its flat trajectory. The fact that the Japanese used hand grenades with telling effect during the war with Russia, and opened a way when field guns and small arms were practically useless, and also the fact that this country is the greatest lover of base ball in the world, has induced the government to experiment with grenades. As grenades are usually thrown b y hand, it is planned to organize a corps of army ball players, to throw the projectiles as one would throw an ordinary base ball, although there is under consideration a design of a small mortar for throwing these projectiles a greater distance than they could be thrown by hand, and yet be light enough to be carried by hand. The grenades as tested by the Ordnance Department were of about one pound in weight, and could be thrown by a muscular man a distance of from 100 to 125 feet, and over obstacles from 50 to 60 feet high. This method of throwing by hand is, however, more or less uncertain, for the reason that the hand grenade is loaded with a high-power explosive, and should one of them be dropped or handled care-lessly, there would follow a terrific explosion, resulting probably in great loss of life. The mortars as used by the Japa-nese were of wood, about three feet long with a caliber of five to six inches. Mounted at an angle of about 55 degrees, grenades were thrown a distance of over 1,000 feet, with a charge of only two ounces of black powder. It is the consensus of opinion of many officers of the army, that such a corps as is planned would be very effective, and the means of quickly reducing a fort which could not be scaled, or one whose location would not permit of the use of field guns. There would be a practical immediate use for grenades in the Philippines, where our troops are almost daily fighting the rebellious natives, who are intrenched in inaccessible places, where field guns could not be used, and where the hand grenade would prove the only effective means of attack. It is stated that' there are over 5,000 motor-boats on the canals of Holland, mostly driven by kerosene motors.