With this explanation in the mind of the general reader, to whom engineering matters do not usually appeal, we may proceed with the progress of our story, and pass on to the year 1730, when a method differing entirely from any that we have yet mentioned was brought forward. Strictly speaking it had nothing to do with steam, but, as we shall see when we come to consider the subject of steam lifeboats, it embodied an idea which could only be satisfactorily employed by the adoption of steam. In the year mentioned there was published a little book under the title “Specimina Ichnographica: or a Brief Narrative of several New Inventions and Experiments: particularly, The Navigating a Ship in a Calm, etc.,” by John Allen, M.D. The author’s idea was to propel a ship by forcing water, or some other fluid, through the stern by means of a proper engine. To this end he experimented with a tin boat 11 inches long, 5 inches broad and 6 inches deep. Placing this little ship into stagnant water, he loaded it until it sank in the water to a depth of 3¾ inches. Into the boat he also placed a cylindrical-shaped object 6 inches high and about 3 inches in diameter and filled it with water. At the bottom of the cylinder was a small pipe, a quarter of an inch square, and this led through the stern of the craft at a distance of an inch and a half below the surface of the water in which the boat was floating. As soon as Allen removed his finger from the outlet of the pipe in the stern the water, of course, ran out from the cylinder, and this action caused the boat to travel, the speed being reckoned, in the case of the model, at about one-fifth of a mile per hour. Although nothing actually came of this theory at the time, it is none the less perfectly workable, with some adaptations, and some of the steam lifeboats, in order to avoid using propellers, which are liable to get foul of wreckage when going alongside a ship in distress, have an elaboration of this principle. They are propelled by engines which work a pump that drives a stream of water through pipes placed below the water-line in much the same manner as in Allen’s model. Allen at first contemplated working the pumps by men, and then causing them to be driven by an atmospheric steam engine. A similar device was employed in Virginia, U.S.A., by James Rumsey in 1787. In his boat water was sucked in at the bow and ejected at the stern. It was found that as long as the vessel travelled at all she went at the rate of four miles an hour, but as she only covered less than a mile and then stopped, it cannot be said that this experiment was conclusive. In 1788, the following year, however, another boat was made actually to go a distance of four miles in one hour, and the device was patented in that country during the year 1791, but Allen had already patented his invention in England thirty years earlier.