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[Book IV.

Applications of Steam.

have seen that the oldest apparatus moved by steam, of which there isany account, was an eolipile suspended on its axis, at once both boilerand engme, (No. 180) and we sball find tbat tlic first attempts to raisewater by the same fluid were made with the same instruments. Indeed,all the early experiments on steam were made with eolipiles, and all thefirst steam machines were nothing eise.

CHAPTER IV.

Employment of steam in former times—Claims of various people to the steam engine—Applicationof steam as a motive agent, perceived by Roger Bacon —Other modern inventions and discoveries knownto him—Spanish steara-ship in 1543—Official documents relating to it—Remarks on these—Antiquity ofpaddle-wheels as propellers—Project of the author for propelling vessels—Experiments on steamin the sixteenth Century—Jerome Cardan—Vaeuum formed by the condensation of steam, known to theAlchymists—Experiments from Fludd—Others from Porta—Expansive force of steam illustrated by oldauthors—Interesting example of raising water by steam from Porta—Mathesius, Canini and Bessou—Device for raising hot water from Decaus—Invention ofthe steam engine claimed by Arago for France —Nothing new in the apparatus of Decaus, nor in the principle of its Operation—Hot springs—Geysers—Boilers with tubulär spouts—Eolipiles—Observations on Decaus—Writings of Porta—Claims of Aragoin behalf of Decaus untenable—Instances of hot water raised by steam in the arts—Manufacture of soap—Discovery of iodine—Ancient soap makers—Soap vats in Pompeii—Manipulations of aneient mechanics—Löss of ancient writings—Large sums anciently expended onsoap—Logic of Omar.

It will have been perceived from the preceding chapter that eolipilesfor blowing fires and for other purposes were formerly common, and conse-quently that people were familiär with the generation of steam, and ofhigh steam too, long before modern steam engines were known. Of theapplications of this fluid to produce motion or raise liquids, during thelong period that intervened between the time of Heron and the introduc-tion of printing into Europe, scarcely any thing is known ; yet there canbe no doubt that it was occasionally used to a limited extent for one pur-pose or the other, and perhaps for both.

As the origin and early progress of the steam engine are necessarily con-nected with this part of our subject, the inquisitive reader will not objectto dwell a little upon it, although some parts of the detail do not relatedirectly to the elevation of liquids.

From the important and increasing influence of the steam engine onhuman affairs, a controversy has arisen between writers of different na-tions respecting the Claims of their countrymen to its invention ; and someacrimonious feelings have been displayed. This is to be regretted asfostering prejudices and passions which it is the province of philosophersto eradicate—not to cherish. National vauntings may form articles inthe creed, as they are made to contribute to the Capital of politicians;but should find no place in that of a savan. Philosophy, like Christianity ,contemplates mankind as one family, and recognizes no sectional boast-ing. Neither Science nor the arts are confined by degrees of longitude,nor are the scintillations of genius to be measured by degrees from the 1equator. As in the republic of letters, so in that of Science and the arts,-