ENOINE FOR RAISING AND LOWERING WEIGHTS. 45 



the cylinder, and equal in length to the height of the head, 

 above the tail water. For inftance, if a column of water of 

 any given diameter has a fall of 20 feet until it reaches an en- 

 gine, its power is clearly afcertained. Now whatever that 

 power is, if a fyphon pipe be added to this engine, fo as to 

 connect with the column, and the fyphon pipe has alfo a fall 

 of an equal length ; namely, 20 feet to the lower end, which 

 is immerfed in water, the engine although placed in the mid- 

 way, will then have a power equal to that of a defcending 

 column of 40 feet, and fhould the column or fall to the engine 

 be but two feet, and the lower fyphon pipe 24- feet, the 

 power would be equal to a fall of 26 feet ; and in this manner 

 in every various diversity between the falling column and the 

 fyphon pipe beneath, the latter will produce an equal power 

 according to its proportionate length, or depth to the furface 

 of the tail water, provided it does not exceed above 30 feet, 

 or the Weight of the atmofphere ; and where a ftream of 

 water is either level with, or even below, the place at which 

 it is defirable to fix the engine, there will be no difficulty in 

 placing it either below, or on the level, or above the ftream 

 itfelf, provided the height where it is fixed above, does not 

 exceed 28 or 30 feet, and the place where the water flows off 

 be ftill lower. The conftruclion may evidently be varied ac- 

 cording to the local fituation and circumitances of applying it, 

 and the ufe to which it may be adapted, in giving activity to 

 different kinds of machinery. 



The drawing, Fig. 1, exhibits the apparatus for raifing or Engine to be 

 lowering weights of any kind, on wharfs or in warehoufes. ufed lnftead °£ 



° , ° r ir -i -i > crane ' ItS ad- 



A man or boy can raiie or lower goods ofr any weight, with- vantages ftateJ. 

 out other exertion than that of merely turning the three way 

 cock M. to an index; in either raifing or lowering, the flop is 

 inftantaneous, by a fmall motion or turning the cock to the 

 flop mark in the index : this moft effectual of flops, or gripe, 

 operates fo quietly and eafy without any jirk, or jarring, that 

 it removes the ufual rifle attending common cranes or machi- 

 nery in which men are fometimes overpowered. Itraifes and 

 lowers goods with thrice the velocity ufually produced by ma- 

 nual labour, yet an engine of dimenfions fufficient to raife 

 feveral tons, may be fo graduated by the perfon at the cock, 

 as to bring it to the fmootheft flowed motion poflible. The 

 faving of labour and time mull therefore be confiderable, the 



rifle 



