AMERICAN INSTITUTE. 587 



Will some ingenious mechanic look into the last new mode 

 of engraving for bank notes, invented in France? A machine, by 

 exceedingly small wheels, produces two hundred thousand diffe- 

 rent combinations of microscopic lines, imitative of the kaleido- 

 scopic figures, in lines, perfect and distinct, and incapable of 

 imitation. 



AN ENTIRELY NEW MECHANICAL POWER FOR MO- 

 TORS. 

 Mr. C. Butler-Clough, Llwyn Offa, Fluit, has invented an im- 

 provement in enlongating and contracting metal bars or rods, to 

 obtain motive power. 



The invention relates to the application and use of tubular bars 

 or rods of metal. Such bars or rods are employed under cir- 

 cumstances wherein great strains are wanted to act in very limited 

 extent, as for instance, in bringing walls of buildings to a verti- 

 cal condition. Heat being used to expand and lengthen these 

 bars, when nuts are screwed on the ends, and by contraction in 

 cooling, the walls are forced into position — an irresistible force, 

 that is, a force equal to the tenacity of the metal. (A bar of 

 Swedish malleable iron of one inch square, sustains 36 tons. One 

 of steel, 67 tons.) Mr. Clough's invention consists in the rapid 

 but uniform expansion and contraction of metal tubes, bars, or 

 rods, by a suitable use of heat and cold. 



NEW STATIONARY POWER. 

 By H. Meigs. 

 Let a very large vessel, perhaps in the form of a scow, be 

 placed in a dock where the tide acts freely. IjQt her lifting 

 power, by the rising of tide, be applied to apparatus of sufficient 

 strength in her centre, and her weight on the fall of the tide. 

 The power, although slow, may be of course applied so as to pro- 

 duce very rapid movements of machinery of moderate power. 

 The vessel will then rise and fall by tides four times a day. 

 Take each rise and fall at six feet, and we have a motive power 

 of the tonnage of the vessel at the rate of two feet per hour, con- 

 stant. The deck of the vessel may be covered with suitable 

 buildings for the desired manufacturing purposes, and in pro- 

 portion to the tonnage of the boat will be the power obtained. 

 The factory, then, without steam, fall of water, wind, or any 

 other force, by gravity and buoyancy, would perform its part as 

 long as the boat will last ard the tides continue. This power of 

 course, will be vastly more important in high tide locations. 



