328 Description of an Invention 



parison thereon, will stand thus : the surface of a body of 

 water of an area of twenty-four inches by ten, is raised 

 about four inches and a half by the power of two pounds 

 descending sixteen inches ; and, vice versa, by reversing the 

 power, the water is again depressed. 



The shuttle i, between the lock and the caisson chamber, 

 will regulate the time of the ascent or descent of the caisson. 



Woburn, April 23, 1805. K. SALMON. 



Charles Taylor, Esq. 



SIR, 



In reading over the copy of the paper which I hastily drew 

 up, and sent with my model, I observe that 1 omitted making 

 any remarks on its applicability, improvements to be made 

 in the carriage to facilitate the moving of the load, and on 

 the different other ways, besides the one shown in the model, 

 by which it may be put in action. 



It will readily occur to every engineer, that this sort of 

 lock is not confined to the particular shape of the model, or 

 to any particular form. The caisson-chamber may be placed 

 endwise to the lock, may be of any shape, and placed at i 

 nearer or further distance, as may be required. 



On comparing the length and movements of the frames 

 in the model with what may be required in practice, it will 

 appear that the lenalh of timbers at large will not be 

 such but that strength sufficient may be obtained for any 

 load. It is also evident, that, although the frames consist 

 of only two bearers in the model, vet, at lanjc, any number 

 may be introduced parallel with each other, and as many 

 wheels as bearers. 



In this operation the weight of the carriage itself con- 

 tr.butes towards the effect, which in common cases is 

 otherwise, as generally there is an objection to the great 

 weight required to make a carriage sufficiently strong for 

 any extraordinary purpose ; and there is no doubt but, by 

 an improvement of the carriage, it mav be made to require 

 .much less than the power used in the present model. The 

 mode I should pursue would be, to make the load in the 

 wheels themselves ; that is to say, the necessary load to pro- 

 duce the effect should be two solid iron cylinders running 



on 



