Considerable progress had within recent years been made in the mechanical appliances intended to replace horses on our public tram lines. The steam engine now in use in some of our towns had its drawbacks as as well as its good qualities, as also had the endless rope haulage, and in the case of the latter system, anxiety must be felt when the ropes showed signs of wear. The electrically driven trams appeared to work well. He had not, however, seen any published data bearing on the relative cost per mile of these several systems, and this information, when obtained, would be of interest. At the present time, he understood, exhaustive trials were being made with an ammonia gas engine, which, it was anticipated, would prove both more economical and efficient than horses for tram roads. The gas was said to be produced from the pure ammonia, obtained by distillation from commercial ammonia, and was given off at a pressure varying from 100 to 150 lb. per square inch. This ammonia was used in specially constructed engines, and was then exhausted into a tank containing water, which brought it back into its original form of commercial ammonia, ready for redistillation, and, it was stated, with a comparatively small loss.