The illustration represents a very simple and inexpensive brake, which by a slight modification may be adapted for use as a foot brake, and which is designed not to cut or wear the material of which the tire is made. The improvement has been patented by Wil liam L. Stewart, of Wilmerding, Pa., and the iIlustra- tion represents the device separately and as applied on a wheel. The brake frame is of metal, and carries ;wo flanged rollers on which is tightly stretched a rub-be,' band, the brake being attached to a stem which extends up the steering head. When the brake stem or rod is forced downward in the usual way, the band bears with eorresponding pressure on the wheel tire. The inventor has also provided a construction by which one of the rollers carrying the band is adjast-able, and may be moved outwardly, if desired, to in-crease the tension on the band. -. Incubation of Diseases. According to investigations made by the Clinical 3ociety,London,the period of incubation for diphtberia does not, as a rule, exceed four days, and is more often two, though it may also extend to five, six or seven; the infection may take place any time in the course of the disease, and mild cases may spread it. In the case of typhoid fever, this may vary within wide limits, twelve to fourteen days, but not infrequently less, and, as the disease is usually introduced into the system by food and drink, it is not carried from one person to another, but several iliay get it from the same sonrce, contaminated water and milk being the usual causes. Epidemic influenza, or "grippe," has for its incubation period a few hours to three or four days, generally striking snddenIy and without warning and a patient may carry infection thoughout the whole course of the disease. Mumps have an incubation period of from one to two weeks and the chances of infection diminish daily. In the case of measles, the period is usually short, being counted from the date of the eruption, which decides the disease German measles have a long incubation period, and the infectidty-diminishes in a day or two after the disappearance of the rash. -m - Substitute for Gold. A French journal describes a new and promISIng substitute for gold. It is produced by alloying ninety-four parts of copper with six of antimony, the copper being first melted and the antimony afterward added ; to this a quantity of magnesium carbonaie is added to increase its specific gravity. The alloy is capable lf being drawn out, wrought. and soldered just as gold is, and is said to take and retain as fine a polish as gold. Its cost is a shilling a pound.