Our story has now brought us to the early part of the eighteenth century. Everywhere men were now trying to make the most of the ideas of Worcester and Papin. The mines were growing very deep. As the water in them was getting beyond control something extraordinary had to be done. Now it seems that whenever the world is in need of an extraordinary service someone is found to render that service. The man who built the engine that was needed was a humble blacksmith of Dartmouth, England, Thomas Newcomen. This master mechanic in 1705 constructed the best steam-engine the world had yet seen. We must study Newcomen's engine (Fig. 7) very carefully. The large beam _ii_ moved freely up and down on the pivot _v_. One end of the beam was connected with the heavy pump-rod _k_ by means of a rope or chain working in a groove and the other end was connected with the rod _r_ in the same way. When steam from the boiler _b_ passed through the valve _d_ into the cylinder (steam-chest) _a_ it raised the piston _s_ and with it the piston-rod _r_ thus slackening the rope and allowing the opposite end of the beam to be pulled down by the weight of the pump-rod _k_. As soon as the piston _s_ reached the top of the cylinder the steam was shut off by means of the valve _d_ and the valve _f_ was turned and a jet of cold water from the tank _g_ was injected into the cylinder _a_ with the steam. The jet of cold water condensed the steam rapidly--steam is always condensed rapidly when anything cold comes in contact with it--and the water formed by the condensation escaped through the pipe _p_ into the tank _o_. As soon as the steam in _a_ is condensed, a vacuum was formed in the cylinder and the atmosphere above forced the piston down and at the same time pulled the pump-rod _k_ up and lifted water from the well or mine. When the piston reached the bottom of the cylinder the valve _d_ was opened and the piston again ascended. Thus the beam is made to go up and down and the pumping goes on. Notice that steam pushes the piston one way and the atmosphere pushes it back. [Illustration: FIG. 7.--NEWCOMEN'S ENGINE, 1705.]