jack boot

This I think necessary to remedy by the scale herewith sent, by which your readers will perceive, that though it is a little larger than a jack boot, as that was necessary for the circumambient steam, yet that it is by no means so large as not to be easily portable, more especially as the pneumatic parts take off, and can be easily placed along with the biler into the inside of the cylinder, and the whole enclosed in a neat mahogany box.