Interesting Experiments in Germany.

In recent years increasing attention has been paid to the many problems associated with the growing demands made upon track and roadbed by heavy locomotives and rolling-stock, and high train speeds. At Home the four group railways have accomplished much in this direction; now the German lines have gone a step further and established, at Cassel, a special laboratory for making exhaustive tests with railway ballast of various kinds.

In the course of a normal year, the German railways spend forty million page 28 marks on ballast renewals. Thanks to modern methods and machinery installed in the new laboratory, it will be possible to ascertain, speedily, the wearing and other qualities of various types of ballast, and determine to just which particular situation each sample is best adapted. One department will be exclusively employed on basalt research, it having been found that basalt, more than other ballasting materials, tends to disintegrate on exposure to air, heat and moisture. To ascertain the resisting qualities of different stones to weather conditions, many ingenious processes will be followed in the Cassel laboratory. Clever machinery will grind the material into sheets of infinitesimal thickness. The sheets will then be examined under ordinary and polarised light, and the results recorded in microphotographic form. Freezing and thawing processes will be practised, and accurate data secured of the capacity of the various materials for absorbing moisture.