60 KANSAS CITY REVIEW OF SCIENCE. 



These sliding-bearings are bolted to the underside of the platform and are 

 forcibly kept at the outer extremity of the supporting-brackets by means of 

 springs coiled thereon. Now, should two cars that are fitted with the platform, 

 be brought together suddenly, as for instance, in a slight collision: the front 

 edges of the safety platforms come in contact first, then, as the movement con- 

 tinues the springs are compressed until the limit is reached by contact of the 

 dead-wood blocks on each car. 



Should the cars be of different heights, the platforms will readily pass each 

 other without compressing the springs, and the apparatus adapts itself easily to 

 all the different movements of the cars, for even when the draw-bars are fully 

 distended there is not sufficient space between the two platforms to permit the 

 passage of a falling brakeman to wheels below. 



No matter how slippery the car-top, or how dark the night, if a brake-wheel 

 is wrenched off by a brakeman he cannot fall under the wheels, the Life-Guards 

 will prevent it ; and although he may slide off the platforms to the side of the 

 track, his injuries will be comparatively slight. The inventor is Mr. Benjamin 

 L. Ferris, of this city. 



Manufacture of Corrugated Metal-Sheets and Securing the Same, 

 WITHOUT Nails, to Buildings. — Hook-shaped fastenings are used instead of 

 nails and stamped depressions along the edge of the sheets are adapted to fit 

 snugly over the fastening-hooks that are previously attached to the timbers of a 

 building. 



The hooks for the ends of the sheets are simply pieces of wrought-iron that 

 are, say, three inches in length, one-half inch in width and an eighth of an inch 

 in thickness, having one end bent to form a smaller hook and the opposite ex- 

 tremity provided with openings for attaching them to the timbers by means of 

 wood-screws. 



The sheets of metal are prepared by running them through a corrugating 

 machine ; this machine has suitable dies upon the rollers which form the depres- 

 sions along the corrugated edge of the sheet as it travels between them. In ap- 

 plying the roofing to a building, a sufiicient number of the straight-hooks are 

 attached to the timbers at such a distance apart as will correspond to every other 

 longitudinal depression in a previously laid sheet, then an over-lapping sheet 

 having the before mentioned indentations along its lower edge, is placed in such 

 a position that the indentures fit within the short hooked-ends of the fastenings. 

 As before stated, the indentations are to make room for the fasteners so that the 

 overlapping sheets will not be held away from the one previously laid, and their 

 overlapping straight edges are secured by means of substantially the same form 

 of fastenings as are used for the corrugated edges, the only difference being that 

 the body of the straight-edged fasteners are curved to fit the concavities of the 

 sheet. 



These fastenings for the straight-edges are placed at suitable distances apart 

 and in applying them a line of sheets having been run up the building, the 



