Page:A Letter on the Subject of the Cause (1797).djvu/39

 would render finally abortive all the efforts it is poſſible to make in giving motion and power to the machine.

This, my Lord, is the mean adopted for giving motion to the external mechaniſm of the Engine by connecting it with the piſton, which is here cloſe ſhut up in the internal part of the cylinder; and as I have already obſerved, the cylinder is placed with its bottom upwards, compared with Newcomen’s, this connection between the internal and external motion muſt of neceſſity be communicated through the bottom which now becomes the top of the cylinder. As the entire effect of the Engine depends on aſcertaining a method of doing this completely, and ſeeming to form the moſt material part of the whole invention, I will be more particular in deſcribing it to your Lordſhip; and begin with ſtating how this was performed by Newcomen.

In all Newcomen’s Engines where the top of the cylinder was entirely open, the piſton was connected with the working beam by a ſingle or double iron chain; in moſt caſes double at the upper end next the beam, and the lower end commonly formed a junction with the piſton