1472,

1543.

2 STEAM NAVIGATION.

instead of oars: the first diagram shows five wheels on each side ofthe vessel, and the pairs are connected by a separate axle runningacross the boat: this axle is formed like a crank in the middle of itslength, and the five axles are connected together by a rod or rope, sothat all their movements are simultaneous."The second diagram ex-hibits one wheel at each side of the galley: these are also connectedby a similar axle, as shown in figure. He supplies no details, butmerely asserts that the velocity of these boats will be found greaterthan if propelled by oars.”*

«“ Blasco de Garay, a Spanish sea captain, exhibited to the Em-peror and King Charles V., in this year, an engine by which shipsand vessels of the largest size could be propelled, even in a calm,without the aid of oars and sails."The experiment was made on the17th day of June, 1543, on a ship of 209 tons, arrived from Colibre,to discharge a cargo of wheat at Barcelona; it was called the Z”rinity,and the Captain’s name was Peter de Scarza. Garay never publiclyexposed the construction of his engine, but it was observed, at thetime of his experiment, that it consisted of a large caldron or vesselof boiling water, and moveable wheels on each side of the ship. Thespeed of the vessel was a league an hour at least.” 7

It is worthy of remark that this account was never published tillthe year 1826, long after the present system of steam navigation hadbeen established; and if such an experiment ever took place, it hasbeen valueless to mankind, as the nature of the invention has beenwithheld.

To accomplish the propulsion of a boat or vessel by means of thesteam engine, it is necessary that the combination of its machineryshould be such as to render it applicable also to the various practicalpurposes for which it is now employed; and if we are to believe thatsuch a vessel as the one here described was actually seen by the Em-

*« De Re Militari;” lib. ii. p. 2. Veronee, 1472,+ See Scott Russell on“ Steam and Steam Navigation,” p. 223, and Stuart’s“ Anecdotes of the Steam Engine,” vol. ji. p. 485.