Luke of Brlclgeviater's underground inclined Plane. 48^ 



at the place where the waggon-ways unite ; and, for the fame purpofe, rollers of eight 

 inches diameter are fixed at intervals down the run of the inclined plane. Moreover, a 

 hollow caft-iron roller of eight inches and a half diameter is fixed acrofs the weft lock, 

 parallel to the upper weft lock-gate, and near the north end of the lock, but half a yard 

 higher than the gate, in order to bear up the rope, and to prevent it from fwagging. 



A hold-faft rope is fattened to the main-rope, to ftay each boat upon its waggon, as 

 they go up or down. It is marked k k, in Fig. 2, Plate XXL and its ufes are more particu- 

 larly detailed in the table of reference, at k k, to that plate. 



Upon this horizontal main-fhaft is a break-wheel above mentioned, which regulates the 

 motion of the loaded boat going down the inclined plane. 



The number of iron teeth, or cogs, in the fpur-wheel, which is fattened to the fide of 

 the break-wheel, is three hundred and feventy-two ; and the little nut-wheel, No. 3, 

 Fig. 4. which fets it in motion, contains eleven teeth, or cogs. The nut-wheel is fup- 

 ported by two uprights from the pillar to the roof, and works between them. Two 

 winches or handles. No. 4 4, Fig. 4. on its axis, put the main-fhaft, d d. Fig. 2. or 

 No. I, Fig. 4. in motion. The power of both united enables a man, who ufes a force 

 equal to forty pounds weight, to fet forward two tons upon the waggon-road : and this 

 force, multiplied at the winches or handles, may be ufed to fet forward the loaded boat 

 out of one lock, and to bring the empty boat into the other. The boats being thus put in 

 motion, the little nut-wheel is difengaged from the main-fliaft, by a Aide drawing the 

 little nut fideways, fo as to difengage the teeth, or cogs, from the cogs of the fpur-wheel. 

 The weight of four tons going down bring up about one. 



The fpur-wheel, however, which is fattened to the break-wheel. No. 2, Fig. 4. is 

 feldom ufed, as it is occafionally only put in motion to regulate the ftrctch of the ropes 

 when new, and to draw the light boat into the lock, when, at any time, it may happen to 

 be over-weighted with materials, fuch as mortar, props, flabs, &c. for the ufe of the 

 higher level collieries, and will not move of itfelf, upon a balance, out of the lower level. 



The length of the carriage, or cradle. Is thirty feet ; its width is feven feet four inches. 

 It moves upon four folid caft-iron rollers, which run upon caft-iron plates ; on one fide of 

 each of which there are iron crefts, which ftand two inches higher than the plates, and 

 prevent the carriage from running off the road. 



The weight of neat coal, contained In the loaded boat, is about twelve tons : the boat 

 weighs about four tons 5 and the carriage, or cradle, in which the boat is placed, when 

 conveyed down the inclined plane, is about five tons:— in all about twenty- one tons. 



At this inclined plane thirty loaded boats are now let down, with cafe, in about eight 



hours } that is to fay, four boats are let down in a little more than an hour. The boats 



■ 



ufed in thefe collieries are of different fizes and dimenfions *, fome will carry feven, fomc 

 eight and a half, fome twelve tons. 



The weight of neat coal, independently of the weight of the carriage and boats which i« 

 let down the inclined plane, in twelve-ton boats, in eight hours, will confequently be three 



Vou IV. — Februa?ly 1801. 3 R hundred 



