engines. Subsequently it was found practicable to increase the speed of the engines up to that of the screw, and gearing was consequently abandoned. Now very slow speed turbines are found to be incompatible with efficiency, and probably will always be so; accurately cut steel gearing comes to the rescue, and I think will be a permanent institution as long as steam is used to propel our ships.
When we pass through the colliery or iron districts we often see clouds of steam blowing off to waste, but there is much less than was formerly the case, because low pressure turbines worked by the exhaust steam from other engines are coming into extended use for utilizing what was formerly a waste product. They are generally employed for the generation of electricity, or for working blast furnace blowers and centrifugal pumps and gas forcers, but recently an exhaust turbine of 750 horse-power has been applied to driving an iron plate mill in Scotland. It is especially interesting because it is the first
