282 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL, 



[September, 



]>iston; so tli;it on the piston approaching either, or when it has 

 nearly coni|ileted either stroke, it becomes suddenly relieved from 

 the pressure of the water it is forcing, by the free communication 

 formed by the double passage C, when the pump piston is in the 

 jiosition shown. The steam piston, thus relieved from its load, is 

 free to be carried through the remainder of its stroke by the ex- 

 jiansion of steam in the cylinder; its further admission having 

 been cut off by the partial movement of the slide-valve D. The 

 expansion of the steam thus completes the stroke of the piston, 

 together with the complete movement of the valve D, and this at 

 however slow a speed the engine may be working. 



The second improvement in pumps consists of an arrangement 

 of the valves, which are placed immediately above the pump, in a 

 circular chamber or cylinder, in which a centre-piece is fixed, con- 

 sisting of four radial partitions, with valve openings, on which are 

 iitted the valves E, E, which are the induction, and F, F, the 

 eduction valves, communicating with either end of the pump. 

 These valves are hinged or pivotted on one side, while their move- 

 ment is confined by suitable stops, which confine them to such a 

 position as to insure their fall on the inclined valve faces or jiar- 

 titions, immediately on the cessation of the flow of water. The 

 supply-pipe, or source from whence the water is drawn, is placed 

 in connection with the passage M, the pipe N being the eduction 

 passage, or that through which the water is transmitted. 



The third part has reference to an improved valve, applicable to 

 pumping engines of the construction represented in the engraving, 

 by which the valve-rod may be worked directly from the piston-rod 

 of the steam-engine. In the ordinary slide-valve, instead of work- 

 ing it directly from the piston-rod, it is necessary to employ the 

 intervention of a lever, or some other contrivance by which the 

 direction or motion may be reversed: as when it is required that 

 steam should be admitted below the piston, the valve moves 

 towards the top, in order to uncover the top, and vice versa; 

 whereas by the construction of the valve D, its motion is in the 

 same direction as that of the piston. This valve D, he denomi- 

 nates a "B valve," from the two hollows g, g, in the face; the oflSee 

 of one of these hollows being to pass steam to and from one end 

 of the cylinder, and the other to the opposite end. It will be seen 

 that in the face of the cylinder, besides the ordinary ports, there 

 are two hollows //, h, which are alternately partially covered, and 

 wholly uncovered at each stroke of the valve, the hollow g^. as 

 shown in the engra\'ing, partially covering the hollow h\ and at 

 the same time the steam passage to the bottom of the cylinder; 

 and the hollow g, at the same time covering the steam passage and 

 the eduction port for the escape of the steam from the top of the 

 cylinder; the position of the valve being the result of the down 

 stroke of the piston. On the piston arriving at the other end of 

 the cylinder, the arm, or tappet on the piston-rod, will come in 

 contact with the collar /, when the position of the valve will be re- 

 versed, and steam opened into the top of the cylinder. 



With reference to the equilibrium ])assages in the pump, he 

 mentions several other modes by which it may be effected, such as 

 a number of grooves in the pump-bairel, of the length required, 

 or by connecting the two ends of the pump by a pipe, in which a 

 valve is opened at the proper time to effect that object; but he 

 jirefers the method shown in the engraving, and in conclusion 

 remarks that he does not confine himself to the precise detail, so 

 long as the peculiar character of the invention be retained, as the 

 same object may be effected by the other arrangements con- 

 templated; but that what he claims as new is, removing or reducing 

 the resistance on the pump pistons at the proper time of each 

 stroke, in order to allow the momentum of the moving parts of 

 the expansion of the steam already within the cylinder, to ac- 

 celerate the motion of the parts as explained, so as to throw the 

 slide-valve across the ports with certainty, whether at high or low 

 speeds; and this he claims, in either of the arrangements men- 

 tioned, or any other substantially the same, by which this accelera- 

 tion of speed of the piston at the end of the stroke may be pro- 

 duced. 



Secondly — He claims the arrangements of valves in which the 

 seats radiate from one common centre substantially, as herein de- 

 scribed. 



On the Preservation of Water, by M. Perinet. — M. Perinet, ex-Professor 

 of the Hopital Mihtaire d'Instruction, has succeeded in preserving water in 

 a sweet state, by placing 1} kilogramme of black oxide of manganese in 

 rach cask of water containing 260 litres. He has kept this water for seven 

 \ear8 in the same barrels, and exposed them to various temperatures; 

 at the end of that time he found it as limpid, free from smell, and of as 

 gond a quality, as at the beginning of the e.\i)eriment. The above is equal 

 to C^ II). 10 a butt of 103 gaUoiis. 



THE EXPOSITION OF 1849 AT PARIS. 



The constant struggle in which our manufacturers are engaged 

 with their foreign rivals, makes it of great importance they should 

 be well acquainted with the steps taken by these latter. It is not 

 enough that we seem to be doing well here; we must be quite safe 

 that we are doing better than others. The mere fact that we have 

 a large market in a foreign country for our cottons, our iron, or 

 our machinery, is an inducement to the manufacturers of that and 

 other countries to wrest the market from us. Knowing, therefore, 

 the interest that attaches to the progress of foreign industry, we 

 felt it our duty to attend the Exposition lately open at Paris; and 

 it seems a fitting time that the whole subject of these expositions 

 or shows should be gone into, as they daily attract more attention. 



The Exposition is one of those measures, having their beginning 

 in the first great French revolution, which were taken to promote 

 the welfare of the people,— and which down to our time, notwith- 

 standing the hostility of kings and the apathy of governments, 

 continue to kee\> alive the great principles that the end of society 

 is not to make the happiness of the few, but of the many. The 

 English have been the great apostles of these truths, and have 

 given the best exemplifications of them; but it so happens, that 

 for many institutions, and the Exposition is one of them, nothing 

 has been done here It was a great thought, amid the din of war 

 and the suffering of a fearful revolution, to give new life to trade 

 by drawing together the products of manufactures, — strengthen- 

 ing public hopes by showing what resources France possessed, — 

 awakening the skill of the man of learning and ability by showing 

 what she still wanted — wherein she was behindhand; where the 

 field needed no further tilling — where it was waste and could yield 

 a good crop. The first experiment was a short one. It took place 

 in 1798, now fifty years ago, and a building was raised at Paris 

 called the Temple of Industry, in which, for three days, the infant 

 Exposition was opened. At that time there were only 110 contri- 

 butors. 



From that time, under the influence of the great patron of 

 French trade. Napoleon, in that as in everything the friend of his 

 country, the Exposition was frequently held, — though it has been 

 said the honours shown to the manufacturers and engineers in 

 1806, drew down the jealousy of the military party. The great 

 war caused it to languish, and it was not until 1819 that this insti- 

 tution, suspicious to the Bourbons for its birth in the days of revo- 

 lutionary freedom, was allowed to revive. From that time, an 

 Exposition has been held every four or five years. It is called the 

 National Exposition of the Pi-oductions of Agricultural and Ma- 

 nufacturing Industry, but agriculture holds only a subordinate 

 place. 



This great show is commonly held in a building set up for the 

 time in one of the great open places in Paris. The first was in the 

 Champ de Mars; those of 1801, 1802, 1819, 1823, and 1827, in the 

 palace of the Louvre; that of 1806 on the Esplanade of the Inva- 

 lides; the one of 1831 on the Place de la Concorde; of 1839, 1844, 

 and 1819, in the Champs-Elysees. The length of the show was at 

 first three days; afterwards, six and seven; in 1806, twenty-four 

 days; in 1819, thirty-five; in 1823, fifty; and since then, sixty 

 days. 



The following will show the progress made: — 



Year of Shou*. Extijbitora. Rewards. 



1798 110 23 



1801 229 SO 



1802 540 254 



1S06 1,422 610 



1819 1,662 869 



1823 1,642 1,091 



1827 1,695 1,254 



1834 2,447 1,785 



1839 3,281 2,305 



18J4 3,960 3,255 



1849 4,532 



The rewards are medals of gold, silver, and bronze, an honourable 

 mention, and a favourable citation. To the name of each exhi- 

 bitor is appended, in the official catalogue, a list of the rewards 

 gained at the Expositions. Thus, Derosne and Call, the great ma- 

 chinists, are named as having gold medals in 1827, 1834, 1839, and 

 1844, showing how long have been their exertions. Japy, brothers, 

 hardware manufacturers, are named as having gold medals iu 1806, 

 1823, 1827, 1834, 1839, and 1844. 



Besides these medals and certificates, the cross of the legion of 

 honour is .ilways given to some of the most meritorious exhibitors. 

 Napcdeon took a great interest in the Exposition. Louis Philippe, 

 however great a tyrant, certainly a friend to the arts of peace, 

 spared no pains in promoting the three great Expositions of his 



