General Notices. 



459 



MISCELLANEOUS INTELLIGENCE. 



Art. I. General Notices. 



Reid's neiv Hydraulic Engine {fig. 120., to a scale of liin. to 1ft.) 

 — Our readers are aware of the important improvement made b}' Mr. 

 Reid in the garden syringe, in 1819, by the introduction of the ball-valve, 

 almost the only description of valve of which it maybe said that it never 

 goes out of repair ; and that it will continue to act perfectly for a life- 

 time, or till the materials of which it is composed decay. Mr. Reid has 

 recently made a great additional improvement in this syringe, by which it 

 is, in effect, turned into a garden engine ; the difference between a com- 

 mon syringe and an engine being, that the latter forces out the water in 

 one continuous stream. Mr. Reid's improvement consists 

 in an arrangement by which a volume of air is compressed 

 to an indefinite extent, by the working of the piston for 

 forcing out the water, and without any sensible increase of 

 labour to the operator. The manner in which this effected 

 will be understood by the diagram 

 fig. 121. ; in which a is thepiston 

 and cylinder, as in the common 

 syringe ; b, a case in which this 

 springe, and also the discharge- 

 tube {c), are enclosed ; d, a small 

 hole in the side of the discharge- 

 tube ; and e, a valve at the bottom 

 of the discharge-tube : / is a 

 valve to the suction-tube, by 

 which the water is drawn up 

 from a watering-pot, pail, or any 

 other vessel. On the motion of 

 drawing up the piston («), the 

 water enters by f; while, by 

 pushing down the piston, the 

 valve at f is closed, and the 

 water is forced up the valve at e, 

 into the discharge-tube ; but, as 



some more water is forced into this tube than can pass 

 through it, it escapes, by the small opening at d, into the 

 vessel of air in which the working barrel and the discharge- 

 tube are encased. As the air cannot escape from this vessel, it 

 is necessarily compressed by the water which enters through 

 the small opening at d; and, consequently, when thepiston 

 («) is drawn up, and no longer forces the water up the 

 discharge-tube {c), the action on that tube is kept up by 

 the expansion of the compressed air which shuts the valve 

 at e, and, consequently, forces the water along c. 



A great beauty in this arrangement is, that no exertion of 

 the operator is lost; nor can he exert himself without pro- 

 ducing a corresponding result ; for if, by rapid and powerful 

 action he drives much water into the air-vessel, the greater 

 degree in which the air is compressed will force the water with the more 

 rapidity through the discharge-tube (c). In this way, it may be said that the 

 superfluous exertion of the operator is not only saved, but turned to powerful 

 account in producing a continuous stream. Mr. Reid states that this saving 

 of labour is one third as compared with other engines of the kind. 



Fig. 120. shows a general view of the engine, to a scale of 1a in. to 1 ft. ; by 

 which it appears to be 3 ft. in length ; and the outer casing is 2\ in. in diameter. 

 It weighs between 5 lb. and Gib.; it works with remarkable ease, and is 



