r. 



or 



extraBing Marine Salt from Sea Water,- j j .^ 



/ ers or roofs fliould be made as light as poffible ; they mufl, 



however, effeaualiy fecure the vats from rain, as that would 

 greatly injure the procefs, by diluting the pickle, and impede 

 ing the evaporation. They are in the form of the common 

 pitched roof with gable ends. They fhould be ten feet in 

 width, fo that a vat one hundred ittx. long, will require ten 

 covers." i:\\t two pieces of crofs joift, which fupport the roofs, 

 are furnilhed with fhivers, or fhiall wheels of caft 

 hard wood, and alio fide Ihivers, placed horizontally^ to accel- 

 erate their motion. Small Urips of plank fhould be extended 

 from the vats, fupported by proper ftands, for the purpofe of 

 rolling off the covers. The roofs have iifually been covered 

 witli ordinary boards, except thofe over the fait room, which 

 we are advifed to Ihingle 5 but a better method unqueflionably 



L 



is,'inftead of boards, to cover the frames with lliingles nailed 

 upon frnall rafters. In either cafe I would urge tlie expediency 

 of painting the roofs white, for the double purpofe of preferv 

 ing the wood, and its power of increafing the refledion of fo 

 larheat. 



IK r 



The invention of the late Hallet Kelly, comes next under 



confideration : he dirc(5ls the vats to be made in the form of 



^ F 



a parallelogram, 20 by 40 feet ; two of thefe join together at 

 their angles, and communicate by a j[pout. At the angular 

 point is ere(fted a perpendicular poll of a proper height, upoa 

 the top of which is balanced a large crofs beam, firmly brac- 

 ed j the covers upon this plan liave hipped roofs, are twenty 



Q 



feet 



