The Explanation of the Machine. (See Plate DX. Fig. 2.) J, Represents the chimney coming from the furnace. B, The tow-boat.
C C, Two pieces of timber, framed together, to carry the machine.
D a, I) and D b, are three wheels on one axis to re ceive the ropes, M F b and F a.
Ha and Jib are two wheels on the same axis with the fans III III, and move alternately in such a man ner, that when the wheels, Da, I) and Db move back ward or forward, they keep the fans 111111 in a di rect motion.
Pb is a rope going from lib to Db, that when the wheels Da, D and Db move forward, moves the wheel Jib forwards, which brings the fans forward with it.
Fa is a rope going from the wheel Ha to the wheel Da, that when the wheels Da, D and Db move for ward, the wheel Ha draws the rope F, and raises the weight G, at the same time as the wheel Jib brings the fans forward.
When the weight G is so raised, while the wheels Da, D and IA are moving backward, the rope Pa gives way, and the power of the weight G brings the wheel lla forward, and the fans with it, so that the fans always keep going forward, notwithstanding the whee14` Da, D and Db move backwards and forwards, as the piston moves up and down in the cylinder.
LL, are teeth for a catch to drop in from the axis, and are so contrived, that they catch in an alternate manner, to cause the fans to move always forward, for the wheel Ha by the power of the weight C, is per forming its office, while the other wheel lib goes back, in order to fetch another stroke.
weight G must contain but half the weight of pillar of air pressing on the piston, because the weight G is raised at the same time as the wheel lib performs its office, so that it is in effect two ma chines, acting alternately by the weight of one pillar of air of such a diameter as the diameter of the cylin der is.
If it should be said that this is not a new invention, because I make use of the same power to drive my machine that others have made use of to drive theirs for other purposes, I answer, the application of this power is no more than the application of any common or known instrument used in mechanism, for new invented purposes.
Answers to some Queries that have been made, con cerning the Possibility and Usefulness of this un dertaking.
Query I.—Is it possible to fix instruments of sufficient Strength to move so prodigious a Weight as may be contained in a very large Vessel ? mechanics will allow•it is possible to make a machine to move an immense weight, if there is force enough to drive the same ; for every member must be made in a proportionable strength to the intended work, and properly braced with laces of iron, &c. so that no part can give way or break. If
the braces, &c. necessary for this work, had been put in the draught, it would have been so much crowded with lines, that the main instruments could not be so well perceived.
Query not the force of the waves break any instrument to pieces that is placed to move in the water? It cannot be supposed that this ma chine will be used in a storm or tempest at sea, when the waves are very raging ; for if a merchant lieth in harbour, &c. he would not choose to put out to sea in a storm if it were possible to get out, but rather stay until it abated.
2dly, When the wind comes a-head of the tow-boat, the fans will be protected by it from the violence of the waves ; and when the wind comes sideways, the waves will come edgeways of the fans, and therefore strike them with the less force.
3dly, There may be pieces of timber laid to swim on the surface of the water on each side of the fans, and so contrived as they shall not touch them, which will protect them from the force of the waves.
Up inland rivers, where the bottom can possibly be reached, the fans may be taken out, and cranks placed at the hindmost axis to strike a shaft to the bottom of the river, which will drive the vessel forward with the greater force.
Query being a continual expense to keep this machine at work, will the expense be answered? Answer. —The work to be done by this machine will be upon particular occasions, when all other means yet found out are wholly insufficient. How often does a merchant wish that his ship were on the ocean, when, if he were there, the wind would serve tolera bly well to carry him on his intended voyage, but does not serve, at the same time, to carry him out of the river, &c. he happens to be in, which a few hour's work of this machine would do. Besides, I know en gines that are driven by the same power as this is, where materials for the purpose are dearer than in any navigable river in England ; therefore, experience demonstrates, that the expense will be but a trifle to the value of the work performed by those sort of ma chines, which any person that knows the nature of those things may easily calculate.