668 
Report on the Exhibition and 
Area dug per hour, assuming furrows to be 200 yards) -, -, 
long S 
Average indicated liorse-power required for this rate) og.g -, 
of jirogress J " ^' ^' 
A few days subsequently to the above trials, viz., on the 15tli July, the 
Darby Digger was taken out to the same ground after continuous heavy rain, 
and worked direct up a hill-side on a slope frequently exceeding 1 in 10 at an 
(■ngine speed of 200 revolutions per minute ; it also worked on the flat, and 
crossed some fallows ; the last-named operation, however, was only done with 
difficulty in the then wet state of the ground. 
Performances of Btm-eWs 10-Horse-Poiver PIougMng-Engine (Everett's 
Patent), icorlcing a Foicler ^-Farrow Balanced Digger (lent to the 
Society by Messrs. Fowler), at Carlisle, July 10, 1880. 
One engine, cylinder 10 in. diameter, 12 in. stroke, boiler pressed to 150 lbs. 
prcssuie. 
Square Feet. 
Heating surface in fire-box .. .. .' 32 
„ in tubes 133 
Total 165 
Fire-grate surface, 5 • 5 square feet. 
The whole of boiler made of Landore Siemens steel. 
Weight complete, including water and coals, 13^ tons. 
Two 11-tooth pinions on engine crank shaft, drive a wheel with 107 teeth 
on each drum. 
Feet. 
Average length of rope wound on drums per revolution) 
of drum during trials ) 
Advance of implement j)er revolution of engine .. .. 1*89 
Digger has 4 breasts, with 
Furrow wheel 5'0 in. diameter, 42 in. broad. 
Land wheel 4'G in. diameter, 5} in. broad. 
Skid wheel 13^ in. diameter, 4^ in. broad. 
Weight, 34 cwt. 
Weight per inch width of tyres, 3C2 lbs. 
Average width dug 40 "5 inches - 3*375 ft. 
Average depth dug 6 "02 inches = •502 ft. 
Weight of unmoved earth per cubic ft 105 •! cubic ft. 
Volume of earth moved per engine revolution .. .. 3^ 20 cubic ft. 
Weight do. "do. .... 336 lbs. 
Mean foot-lbs. of work indicated in engine per revo-) g22]^ ft -lbs 
lution I 
Indicated work in cylinder per lb. of earth moved,! 
or height in feet to which earth moved must bef 
raised to represent work done (mean of 9 indicator | 
experiments) ) 
Average revolutions of engine per minute .. .. 180 
Mean indicated horse-power in straightforward work 44 "8 h.-p. 
Do. do. when dragiiing the rope) jg.g 
and implement light over ground without digging ) " 
llatio of power required to move rope and implements 
without digging to that required when digger is[ ^408 
working 
24^4 ft.-lbs. 
