ABSTRACT
This chapter deals with the discoveries and inventions of the present century. Steam engines are constructed in a great variety of forms, adapted to the purposes for which they are intended. Distinctions are made according as the engine is fitted with a condenser or not. Locomotive engines for propelling carriages on common roads were invented many years ago, by Gurney, Anderson, Scott Russell, Hancock, and others. Besides the steam engines already described or alluded to, there are many interesting forms of the direct application of steam power, such as the steam roller and the steam fire-engine. A cheap and very convenient prime mover has lately come into use, which has certain advantages over even the steam engine. The steam hammer has recently been improved in several ways, and its power has been more than doubled, by causing the steam, during the descent, to enter above the piston and add its pressure to the force of gravity.
