machinery in motion to which the other end of the strap might have been attached. This machine, after a lapse of nearly two thousand years, has been lately revived, and rotary engines, constructed on the same principle as Hero's in many of their

details, are now working in this country. An excellent account of Hero's inventions has been published by Mr. Bennet Woodcroft.

Next in our chronicle of experiments is that made, in 1543, by Blasco de Garay, a sea-captain, to propel vessels by what has been somewhat loosely assimilated to a steam-engine. In going over the ground of history practised writers are continually stumbling. Thus a popular journalist, referring to the above experiment, said: "Three centuries ago Blasco de Garay attempted to propel a boat by steam in the harbour of Barcelona." To this positive assertion it was replied, "The evidence cited by the Spaniards, often repeated, is a letter from Blasco himself." By permission of the Queen of Spain,

but after much hindrance, the person who questioned the statement was enabled to inspect this letter, which is preserved with the archives at Simancas, near Valladolid, and there is not one word about steam in the document. Blasco describes minutely a vessel propelled by paddles, worked by 200 men. It is true that the two letters at Simancas do not mention steam, as pointed out by Mr. Macgregor to the Society of Arts, in 1858; but the account of the experiment, as mentioned by Navarrete, leaves no doubt. We have not space for the entire details. Blasco de Garay is described to have presented to the Emperor Charles V. an engine which he had invented to propel large vessels without sails or oars. The account continues :"The inventor did not publish a description of his engine; but the spectators saw that it consisted principally of an apparatus for boiling a great quantity of water; in certain wheels, which served as oars; and a machine that communicated to them the steam produced by the boiling water." Then we have the treasurer Ravago's objection, that "the boiler continually exposed the vessel to an explosion." The account concludes thus: "These facts are extracted from the original register in the archives at Simancas, among the papers of Catalonia, the register of the War Office of the year 1543." The "cauldron of boiling water" is also mentioned in the account from Navarrete, under "Barcelona," Penny Cyclopædia, vol. iv. p. 438. Mr. Macgregor impugns Navarrete's report; and, as the result of his inquiries in Spain, he attests that not only are the letters at Simancas without evidence of the steam, but the statement is not known there, or at Barcelona, by the public officers. Supposing the evidence to be strictly correct, it bears only conjectural proof of the use of steam, though a boiler was used. Garay took away the machinery. It has been suggested that the moving power was obtained by an apparatus resembling the primitive steam-engine of Hero, just described.

Garay was rewarded, and the usefulness of the contrivance in towing ships out of port was admitted; yet it does not appear that a second experiment was made. The vessel was

found to progress at the rate of a league an hour, or, according to Ravago, the treasurer, who was one of the commissioners, (but unfriendly to the design) at the rate of three leagues in two hours; but it did progress, and was found to be easily under command, and turned with facility to any point where it was directed. Favourable reports were made to the Emperor and

to his son Philip II., but an expedition in which they were at that time engaged prevented the carrying out of the design to any practical extent. Thus the world was in all probability prevented for two centuries from reaping the immense advantages that would have resulted from the adoption of steam navigation.

At the conclusion of the experiment Garay, who was determined to keep his invention perfectly secret, immediately removed his machinery, leaving nothing but the bare wooden framework behind. This discovery, however, was thought so highly of that he was rewarded with promotion and two hundred thousand maravedis, besides having his expenses allowed him.

In the year 1615 a work appears to have been published at Frankfort, written by Solomon De Caus, an eminent French mathematician and engineer, from

a passage in which M. Arago, the distinguished philosopher, claimed

for its author a share of the honour of the invention of the steamengine. De Caus was at one time in the service of Louis the Thirteenth, and afterwards in that of the Elector Palatine, who married the daughter of our James the First. During the latter period he visited this country, and was employed by Henry, Prince of Wales, in ornamenting the gardens of Richmond Palace. The passage referred to by M. Arago is much as follows:-Let there be attached to a ball of copper, a, a tube, b, and stop-cock, c, and also another tube, d; these tubes should reach almost to the bottom of the copper ball, and be well

soldered in every part. The copper ball should then be filled with. water through the tube, b, and the stop-cock be shut, when, if the ball is placed on a fire, the heat acting upon it will cause the water to rise in the tube, d, as indicated in the engraving. De Caus ascribed the force entirely to the air,

and not to the steam, which he does not mention, though the pressure may have caused the ball to burst with a noise like a petard. Notwithstanding the advocacy of M. Arago, De Caus is not entitled to any share in the invention of the Steam-engine.

A few years after the appearance of De Caus's work an Italian engineer, Giovanni Branca, proposed a machine consisting of a wheel with flat vanes upon its rim, similar to the boards of a paddle-wheel. The steam was to have been produced in a close vessel and made to issue with considerable force out of a tube directed against the vanes, which would cause the revolution of the wheel, the tube projecting from the mouth of a figure; but the steam had to pass through the atmosphere in its passage to the wheel. This method bears no resemblance to any application of steam-power in use in engines of the present day.

We now come to the more interesting claim of one of our own countrymen to the honour of being regarded as one of the chief inventors of the Steam-engine. Such was the Marquis of Worcester, who, living in the time of the Civil War between Charles I. and his Parliament, took part with the King, and after losing his fortune in the cause, was imprisoned in Ireland; he managed to escape, and fled to France, whence, after spending some time at the Court of the exiled Royal Family of England, he returned to this country as their secret agent; but, being detected, was committed prisoner to the Tower. It is said that during his captivity, while he was engaged one day in cooking his own dinner, he observed the lid of the saucepan was continually being forced upwards by the vapour of the boiling water. Having a turn for scientific investigation, he began to reflect on the circumstance, when it occurred to him that the same power which was capable of raising the iron cover of the pot might be applied to useful purposes; and on obtaining his liberty he set to work to produce a practical exposition of his ideas on the subject in the shape of a working machine, which he described in his work in the following terms:

"I have invented an admirable and forcible way to drive up water by fire; not by drawing or sucking it upwards, for that must be, as the philosopher terms it, intra sphæram activitatis, which is but at such a distance. But this way hath no bounder if the vessels be strong enough. For I have taken