C 365 ]

brafies the fame way as the water-wheel, will work mere eafy and pleafant, and be lefsliable to get a (hake, and be out of order by continuance of wear : The whole, there-fore, of the motions being performed with more eafe and fimplicity than No. 1, I ex-peft it to be fubjeft to lefs attention and repairs, and that it. will not require above 4.of the water to work it, taken by No. 1.

There will be more timber in the framing, but as it will be nothing but commonfir timber, 1 apprehend this will be no objeft, and this will be more than faved in thewater-wheel and axis, the lpurn-wheel, and pinion.

No. 1 is a defign for the upright of the water-wheel; it is here fhewn to be of 20feet diameter, but as, on my laft view at Carr on, 1 underftand that the wheel No. %lays lower than the reft, and is fometimes affected by tail water, .when Stenhoufe mill-dam is full, a circumftance I was not before apprifed of; in order to avoid that, it may,perhaps, be necelfary to reduce the diameter of the new wheel from. 20 feet to 19 feet6 inches; but, yet, if Stenhoufe mill-dam never throws above 3 inches dead water uponthe bottom of theprefent wheel, then the new wheel may be laid as low as the prefentwheel, becaufe that quantity of dead water, fuppofing the tail water-courfe from thewheel be open and free, will be of no prejudice to the going of the new wheel.

The reduction of the water-wheel to 19 feet 6 inches is, again, only upon a fuppofitionthat the pond is fubjeft to be reduced. 1 fo t 9 inches below head, as I faw it the 7thinftant; but if it is never fuffered to go above 1 foot below head, as advifed in my re-poit of this day, or, at moll, 14 or 15 inches, then the water-wheel may be of its full,fize, though it fhould be obliged to be raifed at the bottom from 3 to 6 inches, tofufficiently clear the tail water.

The elevation here given is fuppofed to be of the outward front, but as I find thetail water goes off the contrary way to what is here fhewn, and will require a differentkind of penftock, for which I will fend a particular defign when I return to England,it will be proper, to lay a fweep to the breaft of this wheel, to fit it as clofe as poffible,but it may either embrace the wheel a quarter round, or only 4. of the circle as is foundmod convenient in the execution; the twq different ways are fhewn according to theletters ABC and A D E.

The width of the wheel is fuppofed to be as great as the conduit will allow, as itwill work fteady like No. x, no allowance need be made for fhake.

No.