Bologna Stone 429 Foundling Hospitals 434 Orphan Houses 449 Infirmaries. Hospitals for Invalids. Field Lazarettos 454 Cock-fighting 473 Saltpetre. Gunpowder. Aquafortis 482 Book-censors 512 Exclusive Privilege for Printing Books 518 Catalogues of Books 522 Ribbon-Loom 527 Guns. Gun-Locks 533 THE STEAM-ENGINE, AND THE DISCOVERIES OF JAMES WATT. Although the plan of this new edition of Beckmann’s ‘History of Inventions and Discoveries’ was to confine it to the subjects treated of in the original work, yet we feel it imperative to make an exception in favour of the _Steam-Engine_, the most important of all modern inventions. The power of steam was not entirely unknown to the ancients, but before the æra rendered memorable by the discoveries of JAMES WATT, the steam-engine, which has since become the object of such universal interest, was a machine of extremely limited power, inferior in importance and usefulness to most other mechanical agents used as prime movers. Hero of Alexandria, who lived about 120 years before the birth of Christ, has left us the description of a machine, in which a continued rotatory motion was imparted to an axis by a blast of steam issuing from lateral orifices in arms placed at right angles to it. About the beginning of the seventeenth century, a French engineer, De Caus, invented a machine by which a column of water might be raised by the pressure of steam confined in the vessel, above the water to be elevated; and in 1629, Branca, an Italian philosopher, contrived a plan of working several mills by a blast of steam against the vanes; from the descriptions, however, which have been left us of these contrivances, it does not appear that their projectors were acquainted with those physical properties of elasticity and condensation on which the power of steam as a mechanical agent depends.