ram. of mercury, and the apparatus will withstand wide line-voltage fluctuations without becoming disarranged in any way.
A Novel Device for Preventing the Washing of Roads. H, G. SlttlRLEY. (Maryland State Roads Commi,~sion.)--A novel and practical device is used in the State of Maryland to prevent the washing-out of road shoulders and gutters. These " breakers," as they are termed, answer their purpose so well that they will pay for themselves after two or three heavy storms. They are considerably cheaper than cobblestone gutters, give thorough protection to the shoulders of the road, and may be used on any type of highway, including farm lanes and driveways.
The breaker consists of a low concrete barrier extending from the edge of the road diagonally through the shoulder to the ditch. It is built flush with the surface of the road shoulder, and where the highways are patrolled and the shoulders kept in repair it is no objection to travel. Breakers are spaced as occasion may require, and are neither expensive nor difficult to build. The Maryland breakers are 12 inches wide and 18 inches deep. The spacing varies with the nature of the soil, grade, and amount of water they encounter. Thus it would probably be necessary to space them closer at the bottom of a hill than at the top. On 5 or 6 per cent. grades and medium soil they are spaced 25 to 30 feet apart. Where the soil is liable to wash and the grade is steeper they would be spaced much closer. The length as well as the grade of a hill would also influence spacing.