| Description | 2 sheets. The two sheets were sent separately. Docketed “State of some mines and engines.” Summarised “Boulton’s remarks upon the great length of pump rods and the depth of mines under the sea, and also upon so many of the mines dying. Remarks upon the winding engine. Upon the life of timber beams and the cost. The planet wheel presses hard on the sun. 700 lbs. of lead put on the rod. Suggests the rods are made of iron for the future.” |