126 ANNUAL OF SCIENTIFIC DISCOVERY. 



below by means of stoking bars worked with the hand in a kind of recurved 

 funnel, with open sides, and extending to the grating on that side. This 

 method was long ago suggested by Franklin ; but the arrangements here 

 adopted are peculiar to this inventor and attain perfectly the end proposed. 



IMPROVEMENT IN STEREOTYPING. 



One of the persons employed in the State printing office of Vienna has made 

 the discovery that plates of plaster of Paris will uniformly contract by a repeated 

 washing with water, and still more if with spirits of wine. On this is based a 

 process to produce both print (drucksacheri) and woodcuts in various gradations 

 of type and size, by a calculated diminution of the plaster of Paris plate. 

 Already print and drawings have been made of a twelfth-part size, reduced 

 from three inches to one inch in diameter, and yet even, the reduction to the 

 smallest size does not encroach on the perfect correctness of the impression. 



HYDRO-STEAM ENGINE. 



A very peculiar and apparently effective combination of the steam engine 

 and Turbine water wheel called the " Hydro-Steam Engine," has recently been 

 invented by Mr. 'William Baxter, of Paterson, N. J. The invention, which 

 is especially adapted for the driving of propellers, is constructed as follows : 



Two steam cylinders are placed vertically and parallel to each other, united 

 at the top by a valve chamber and the steam and exhaust passages, and at the 

 bottom by the Turbine wheel chamber and valve cases for the induction and 

 eduction of the water. There is a short stem or rod through the stuffing-box 

 of each cylinder head, answering to the piston rod of the ordinary steam 

 engine, intended for the operation of the slide valve, which lies horizontally on 

 its seat, its stem running through a stuffing-box at each end of the valve chest. 

 Two quadrant pieces or right angled levers jointed on the outside of the chest 

 and immediately over the steam cylinders, one at each end, communicate an 

 alternate motion to the valve, they being struck by the upward motion of the 

 short stems or rods which pierce the cylinder heads : these rods again are 

 operated by the upward motion of the pistons, which work without rods or 

 any outward connexion whatever. Steam is admitted only to one side of the 

 pistons, the other being in contact each with a column of water ; which water 

 is continually forced through the Turbine wheel and thus producing a rotatory 

 motion, proportioned in velocity to the pressure of the steam in the cylinders, 

 and to the size of the Turbine water -wheel. 



The steam acts upon the pistons in the manner of a direct action pump, one 

 end of the cylinder being used for steam and the other for water. The same 

 water is used all the time, it being forced alternately through suitable valves, 

 easily understood by those acquainted with such matters the curvature of the 

 blades of the deflecting guide wheel directing the water on to the curves of 

 the wheel buckets. "Water being nearly an incompressible body, an air 

 chamber is necessary, as in all forcing pumps, to maintain a uniform current, 

 and also to secure a certain degree of elasticity, without which there would be 

 some danger of rupturing the parts. The primary object to be gamed by this 

 new motor is the doing away with a multiplicity of parts. 



