We are informed that a steam tram car has been invented at St Louis, United States, which travels seven miles in fifteen minutes. The boiler, cylinder, coal-box, and water-barrel are ingeniously planned to occupy as little space as possible; and the inventor states that 'under ordinary circumstances the cost of fuel will not exceed three shillings a day.' For further particulars, inquirers must write to St Louis. On looking at a map, one often feels a desire to tell off-hand the distance between two places. Among the instruments exhibited at Falmouth, Morris' Patent Chartometer, which may be carried in the pocket as easily as a watch, will enable any one to get the desired information. The 'works' of the chartometer are moved by a wheel projecting on one side. To measure any distance on a map, we are told it is only necessary to hold the instrument upright, and run the wheel along the line between two places, or the course of a river, or the sinuosities of a coast, and the indicating fly denotes the number of miles or parts of a mile. The distance is shewn at once, without the trouble of calculation, which is an important advantage. A Patent Measuring Instrument, by the same maker, is described as 'somewhat similar in character, being run along the surface to be measured. It measures up to one hundred feet; and is of the size of an ordinary watch.' The practice of using leather belts for transmission of power in foundries and factories, which prevails largely in the United States, has been imitated in Lancashire and Yorkshire with satisfactory results. With belts there is less noise and less vibration than with iron shafting and bevelled wheels; the walls of the building are consequently not weakened by perpetual shaking, and diminution of roar and rattle cannot fail to be a benefit to all concerned. Nevertheless leather belts are costly articles, and if hemp could be substituted for leather there would be a saving of two-thirds of the cost. This has been proved in Dundee, where in one of the factories (Messrs A. & J. Nicholl's) rope-gearing is used for transmission of power to all parts of the building, and during an experience of five years, has given full satisfaction. The size of the ropes varies with the work required; the largest, in the instance here under notice, being six and a half inches circumference. The power is communicated directly from the fly-wheel, the rim of which, instead of cogs, is filled with circumferential V-shaped grooves. The 'life' of a rope is said to be from three to five years, though some ropes last much longer; which considering that they travel from three thousand to six thousand feet per minute, may be regarded as long enough.