We are in receipt of several communications relative to the construction of roadways for velocipedes. Among the most feasible of these is one from an Albany correspondent, who recommends a way consisting of a single plank in width, laid so as to be nearly or quite level with the ground, one on either side of the street, so as to permit of travel both ways. The plank need not be more than an inch and one-half in thickness, cleated in the back to prevent warping and springing. Another suggests rails, the wheels of velocipedes to be flanged, a plan, which, with some modifications, has been proposed in England. Indeed, an application for a patent on a velocipede railway, has been made to the Lord Chancellor of England/of which the following is a description: One single line of rail is arranged in the middle of the roadway. The rolling stock is constructed with four bearing wheels, with double flanges, all in one line in the middle under each carriage, instead of having bearing wheels placed on each side. Traversing screws and gear are employed for shifting the wheels laterally, relatively to the body of the carriage, until the load is perfectly balanced on the wheels. The perpendicular position is still further preserved by the addition of one or more wheels on each side of the carriage, so arranged by working in slots, as to run freely upon the road without bearing any part of the weight of the carriage, except when the carriage inclines to one side or the other. Another correspondent suggests the Croton aqueduct, from the Westchester side of Harlem river to Central park, in New York city, as a grand " boulevard" or highway for velocipedes; the top of the aqueduct to be covered with Nicolson pavement, having a strong and ornamental rail on each side, with a low central rail to divide the up and down travel. We regret that, delightful as would be such a velocipedal Utopia, the expense connected with the scheme compels us to pronounce it impracticable. We give herewith an engraving of a water velocipede, devised by a Boston inventor, which is a very neat device. It needs no detailed description, as its operation will be readily comprehended from the engraving. The rudder is worked by two cords passing from the steering bar, over pulleys fixed upon the side of the boat below and in front of the operator, and from thence back to the tiller. The Hamilton county Evening Times has an account of a velocipede which it says " may be classed in the genus Veloci-pedus giganticus, is fashioned with three wheels, two large ones, of over six feet in diameter, and one small wheel forward, working on a pivot, by which the establishment will be guided. The locomotive power is communicated to the axle of the large wheels, by means of four treadles, two persons being required to drive the machine at full force, who are comfortably seated in an ordinary carriage-seat over the axle. A third passenger may be accommodated on a forward seat, and manage the steering apparatus, or either such assistance may j be dispensed with. An ingenious arrangement is attached to j the axle, by which the treadle power can be thrown off when descending declining ground, and the establishment be allowed to run by its own momentum. It thinks that gigantic velocipedes may be immediately constructed on this principle, with wheels from twenty-five to thirty feet in diameter, to supersede those old-fashioned abominations, the ordinary stage coaches, and to be propelled by the passengers themselves. The number of velocipede halls in New York and Brooklyn is now about thirty, and " still they come." Most of them are schools of instruction, where, for a moderate fee, the most ! awkward individual in existence, can be taught the management of the erratic, but not untamable, iron steed. An important fact was elicited at a recent display of velocipede riding on Clinton street, Brooklyn, and that is, that the large wheeled velocipedes ride easier and go faster than the small wheeled machines, even when the latter are ridden by the bestrideis. Another important fact, developed by the experiment's, that an effective brake on the hind wheel is positively necessary. We have not yet seen a brake which had enough iron to cover the tire of the wheel with. All those now in use scarcely have an inch of iron surface to bear on the wheel, when four times the amount would not be too much. The leather thongs, too, connecting the brakes with the guiding arms, should be replaced by the wire cord, as it is absolutely necessary that .the brake cord should be made of material that will not give way, A slight grade affects the progress of the small-wheeled velocipedes considerably, an effort being required to propel a machine from Atlantic street to Montague, while, on the other hand, a man can start from Montague street to Atlantic, and go all the way without using the treadles or putting his feet to the ground. The rule is, that the larger the wheel the easier a grade is ascended. It was decided by a unanimous vote that good spring seats were requisite on the Nicolson pavement. A noteworthy feature of the display was the fact that not a solitary horse shied at the velocipedes, much to the disgust of the old fogies, who had prophesied that bicycles would lead to endless accidents from frightening horses in the street. As some physician of this city has been publishing a sensation statement about certain injurious effects likely to occur from the use of the velocipede, the following from a leading practitioner may serve to counteract any fears that may havo been created in the minds of the timid. He says: " I look upon this mode of exercise with this physiologically constructed machine, as one of the most brilliant discoveries of the nineteenth century; the grand desideratum that will emancipate our youth from muscular lethargy and atrophy that are so common." The Ironmonger, an able London periodical, thus speaks of the utility of the velocipede: " Recognizing, as we do, in the velocipede a positive addition to the locomotive powers of man, we feel justified in again recurring to the subject, more particularly with the view of placing our readers en courant with what is being done to meet present requirements. Since our last issue new evidences have been presented,that, although England has been slow to follow the movement in France and the United States, a general demand is springing up, so much so, indeed, that our velocipede manufacturers experience already the greatest difficulty in supplying orders. We hear of Sheffield and Birmingham houses being engaged to fulfill the orders of London manufacturers, while velocipedes are being daily imported from France. Already West-end and City clubs are forming; and if there is no intention, as in France, of seating professors of the noble art of 'velocipeding' in the chairs of colleges, there is every prospect that large training schools will shortly be opened. Nor is this remarkable ; the velocipede is already recommended by convenience, utility, and economy." To this may be appropriately added the statement of the Velodpedist, for March : " The shipment of velocipedes from this country to England has commenced.; the Inman steamer of Saturday last took a * Pickering' machine, which is to be followed by others as soon as completed." We have received the following communication : Messrs. Editors : There is to be erected here a large rink, and the committee desire to be informed where rubber tiro can be procured and put on to velocipedes. If you will be kind enough to refer us to some one who can do it, you will very greatly oblige a subscriber to, and an admirer of the Scientific American. Geo. A. Coles. Middletown, Conn. Having referred this communication to a prominent rubber manufacturer, we were informed that he knew of no place where these tires could be obtained. Every velocipede manufacturer in the country is trying to get this done, but none of them have as yet succeeded. It is a difficult job to do. --------------------------*.- . ^------------------------ A Sill : Community in California, The latest and most novel idea in the silk culture is Mr. D. F. Hall's embryo " silk community." According to the Los Angeles Star, Mr. Hall has bought a large tract of land, forming part of the San Jose Ranch, about thirty-two miles east of Los Angeles. He proposes to lay off the entire tract, which is two miles and a quarter one way, by one and a quarter the other, into blocks and streets of suitable dimensions, for the convenience of the residents, and offer it for sale to actual settlers. The blocks will be forty acres in size, to be subdivided into lots of from one to ten in size. Ten-acre lots will only be sold to those who will make improvements thereon. " There are certain benefits to be derived from a settlement of this kind, entering upon and making a specialty of the silk I culture, that will particularly commend themselves to these I wishing to enter the business, and particularly immigrants | from the densely populated countries of Europe. For an extensive cocoonery, but a comparatively small quantity of land is required, as it is computed that seventy-eight tuns of mulberry leaves will produce one million cocoons, and that three acres planted in mulberries will yield ninety tuns of leaves. Upon this basis a ten-acre lot will be ample for producing three millions of cocoons, leaving sufficient spare grounds for buildings, fruit, and flowers, without which, no place is fit to be called home. By this small subdividing, the community-will have all the enjoyment of suburban life, with the benefits of churches, schools, lyceums, libraries, etc., etc,, all of which are the necessary adjuncts to an enlightened, prosperous, and happy community."