off the water or sediment, in case foul water be used by accident or carelessness. These two openings through the condenser and air-vessel, and through the boiler, constitute one fire doorway through all the six tubes for access to the fire-place; a ring is placed between the two tubes of the condenser around the fire doorway, so as to cut off all communication of the steam in the condenser with the air in the doorway; another similar ring is placed between the condenser and the outer tube to prevent the escape of air into the fire doorway, and a half ring is placed in the lower part of the fire doorway between the condenser and the inner tube of the air-vessel, to prevent ashes from falling into the air-vessel, and yet allow a free passage for the air from the inner part of the air-vessel into the upper part of the fire doorway. These two rings and the half ring are secured in their places by rivets passing through all of them and through the tubes, and uniting all firmly together, the interstices being filled with iron cement. A ring is also placed between the boiler and the air-vessel around the fire doorway, against the outside of which ring the charcoal powder is tightly rammed, and will hold the ring in its place without the necessity of either rivets or screws. That part of the fire doorway which is above the fire-bars is supplied with an inner door, to shut the fire-place even with the outside of the boiler, and exclude all access of air to the fire, except through the grating. The whole of the fire doorway is enclosed by an outer door even with the outside of the air-vessel, to exclude all air, except that which comes through the air-vessel; a pipe is fixed in the bottom or dish-piece leading to a forcing pump to draw the water out of the condenser and force it into the bottom of the boiler through the pipe before described. A blowing cylinder of about ten times the content of the main cylinder is screwed against the outside of the air-vessel, and opposite to the two outlet valves of the blowing cylinder two apertures are made in the air-vessel, through which the air is forced in. The main cylinder of the engine, of the usual dimensions according to power wanted, is also screwed against the outside of the air-vessel high enough above the blowing cylinder to allow room for the main-crank shaft to work between them. The forcing pump before mentioned is also screwed to the outside of the air-vessel, and thus my improved steam-engine becomes more compact and convenient than any preceding steam-engine. For the purpose of supplying the boiler with distilled water, in case there should be a deficiency in it, a small vessel made of two upright tubes, one within the other, is placed on the cap-piece. The inner tube is of the same diameter as the flue, and forms a continuation of it. The outer tube is about 6 inches larger than the inner, and the space at the top and bottom between the two