520 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[Oct. 



end of which is a valve / opening outwards. Then if we suppose the cylinders 

 to be full of water, and the piston at the top of its stroke, when it is pushed 

 down it will force a quantity of water into the large cylinder, nearly equal to 



the difference of the solidili/ of the two parts 0/ t/te piston d e, which will be 

 a very little if the two parts rf and e, are nearly alike ; thus giving it the ad- 

 vantage of a small piston while it still possesses the strength of a large one. 

 I have not marked the handle and other parts as they do not differ from the 

 usual construction. 



A M'ORKING MeCH.WIC. 



Neu'castle-OH- Tyne. 



[The above suggestion is very ingenious, and appears likely to prove 

 valuable. .4s the principle of the press in its improved form is to pump into 

 the main cylinder a quantity of water equal in volume to the differeitce be- 

 tween the solid contents of the two pump-pistons we have ventured to apply 

 the name Differential Hydraulic Press 



During the military operations of the French in .\lgeria it was necessary to 

 export from France hay for the cavalry liorses, and in order to compress the 

 hay into the smallest possible compass, it was subjected to the action of the 

 hydraulic press. But it was found that the operation was excessively slow, 

 as during the first part of it a very large quantity of water was pumped in 

 with little or no resistance from the compression of the hay. A similar diffi- 

 culty frequently occurs on less important works tlian that of maintaining a 

 new colony, and a very simple addition to the pump here desciibed would 

 probably remedy the evil. 



Let the cylinder to be continued down into the space s, and let this lower 

 cylinder communicate by a pipe, having a stop-cock, with the reservoir, and 

 also by a pipe similar to k, witli the main cylinder. When the pressure at v 

 is small a large quantity of water may be pumped in at each stroke, and if 

 the stop-cock be open, the upper and lower pump pistons will both draw 

 water. When the pressure at v becomes great, the stop-cock may be closed 

 and water will be forced from the upper pump cylinder only. 



By this contrivance two relative rates of working are obtained. Three or 

 more rates of working might be obtained by having three or more sires of 

 the pump-piston and a corresponding number of cylinders.] 



REGISTER OF NEW PATENTS. 



If additional iofonn&tion be required respecting any patent, it may be obtained at the 

 oflGce of this jouruiil. 



HEATING BV HYDROGEN. 



Joseph Pierre Gillaro, of IJue Martignac, Paris, professor of ma- 

 thematics and philosophy, for " Improvements in the produclion of Heat in 

 general." — Granted February lllh, 1846; Enrolled August Uth, It546. 



The improvements relate to the application of pure hydrosen for heating 

 apartments, steam eugiues, furnaces fur smelting, and other purposes. The 

 hydrogen is obtained by driving jets of steam lhrou;<h red hot retorts con- 

 taining thin iron plates, when the oxygen of the steam forms an oxide on 

 Ihe iron, and the hydrogen of the water is set free and carried oil" by pipes 

 to suitable gasometers. Another process for obtaining hydrogen is by 

 injecting steam, %vith pulverized coal or coke, into red hot retorts, by which 

 means carbonic acid and carburetted hy<lrogen gases are formed ; these 

 gases are carried oU' by pipes to a purjtier containing lime-water, when 

 the carbonic acid is absorbed, and the carburetted hjdrogen carried with 

 another jet of steam throuj;h a second red-hoi retort, when the carbon is 

 decomposed and united with the oxygen of the steam forming carbonic 

 acid, and at the same time the hydrogen of both the steam ur.il the carbu- 

 retted hjdrogen is liberated; thus pure hydrogen is obtained, which is 

 carried off to tlie gasometer, and at tlie same time the carbonic acid is 

 passed to a second purifier, where it is absorbed. 



For healing apartments two pipes and two gasometers are employed, 

 one furnished with hydrogen, and the other tilled with atmospheric air; 

 the pipes are so conveyed to jets at the sp^t, that the gases may be 

 mixed before the combustiou takes place. Two volumes of air to one 

 of hydrogen will be required for proper combustion. 



For locomotive engines, there are to be introduced into the space occu- 

 pied by Ihe firebox, four or five reli.rts, as first described, for obtaining 

 hydrogen ; and the tender is to ha\e two or three gasometers, to hold the 

 hydrogen ami atmospheric air, from which the gases are to be conveyed 

 by pipes to burners lu the engine, for heating the retorts red hot, and at the 

 same time the water in the boiler. When the steam from the engine-boiler 

 has passed through the cylinders, instead of its escaping into the open air, 

 it is to be conducted by pipes to the retorts, where it is decomposed, and 

 the hydrogen passes from the retorts by pipes to the gasometers in the ten- 

 der for suppljiog the engine. 



ZINC PAINT. 



James Mirdock, of Staples-inn, INIiddlesex, mechanical draughtsman, 

 for " an Improved process for jireparitig a certain material for the purpose of 

 painting." (A communication). — Granted February 11; Enrolled Aug. 

 11,1846. 



This invention relates to obtaining pure oxide of zinc, to be used for 

 painting instead of white lead. Zinc, or zinc ore, is put into a tire-clay 

 retort, open at both ends; at one end the chaige of zinc or ore is placed 

 and then sealed up ; the other end is left open, and communicates with a 

 chamber. M'hen the retort is heated, the zinc passes off in a state of 

 vapour, and as it comes in contact with the atmosphere it unites with the 

 oxygen of the air, aud forms the oxide of zinc, the vapour floating in the 

 chamber like a while cloud. For Ihe purpose of collecting the oxide, a 

 series of tine wire sieves are placed in a passage leading into another 

 chamber; this chamber communicates with the large chimney of the 

 retort furnace, and thereby causes a strong draught of air to pass from one 

 chamber to the other, through the wire sieves ; in doing this, the current 

 of air carries with it the fine particles of the oxide of zinc, aud deposits 

 them on the wire sieve.=, which are occasionally shaken to prevent their 



MOTIVE POWER. 



James Nasmvtm, of Arundel-street, Middlesex, gentlemau, for "certain 

 Improve merits in engines or machinery for obtaining and applying motive 

 power." — Granted Feb. 16th; Enrolled August 10, 1846. (Reported in 

 Patent Joiirnnl.) 



These improvements consist in the construction aud working of engines 

 in a novel manner, by the agency of steam or other elastic fluids, or other 

 means, whereby a greater amount of power is obtained than by means 

 ordinaiily employed. In this iraiiroved plan, two, three, or more cylinders 

 may be employed, as may be required, aud the power of the motive agent, 

 whellier it be steam, air, or gases, or any other pressure, is made to act 

 alternately, first at one cud of ihe train of cjlinders, aud then at the oppo- 

 site end, that is to say, if there be two cylinders connected together by a 

 tube, the motive agent is admitted alternately above the pistou and at the 

 upper end of each cWinder, each being in laruo alternalely. If more 

 than two cylinders are uaeil, tliey are put iu connection with each other by 

 means of tubes, the addilioiial cylinders, whatever may be their number, 

 are always iu pleno (that is to say), they are filled with air, or some other 

 elastic or non-elastic fluid, the pistons of which cylinders move up and 

 down simultaneously with the two end cylinders. The pistons of tlie two 

 end cylinders I'r of those which are alternately in vacuo as before explain- 



