58 The Evolution of Agricultural Imjylemerds. 
still an extraordinary fascination for certain inventors is shown 
by the persistent appearance at agricultural shows of steam 
digging-machines. These implements, ingenious and mechani- 
cally meritorious as many of them are, have, as yet, accom- 
plished little, although it must be said that both the Darby 
and Proctor “ Diggers,” making use of steam-driven spades, 
are interesting improvements on the earlier machines of this class. 
Cultivators — sometimes called “ Grubbers,” or “ Scarifiers,” — 
are tillage implements having strong curved teeth, capable of 
penetrating and stirring the land as deeply as the plough, 
whose operations they may either supplement or supersede. 
The cultivator frame is carried upon wheels, which prevent its 
curved teeth from burying themselves in the soil, as they would 
do if left unsupported ; and these wheels are capable of being 
lowered, or raised, for the double purpose of determining the 
depth of the cultivation and enabling the machine to travel. 
Finlayson’s Grubber, patented in 1824, was simply a large 
harrow, with curved teeth carried on three wheels, each about a 
foot in diameter, of which the leader, having an axle mounted 
on a bell crank, could be thrown up and down by means of a 
lever raising the tines sufficiently to enable the machine to be 
turned in at the headland. When travelling, the hind wheels 
were raised by a rack and pinion. 
Scoular soon improved on this arrangement by mounting the 
hind wheels as well as the leader on bell-cranks, all operated by 
the same lever, giving a parallel lift by means of a device which 
has not since been surpassed in simplicity. In the “ Uley 
Cultivator,” first shown in 1843, Earl Ducie carried the rear of 
the grubber upon a pair of wheels furnished with a cranked 
axle, the crank itself being connected by means of a sway-bar 
with the axle of the leading wheel in such a way that this, 
moving in a vertical slide, was caused to rise and fall jmri passu 
with the cranked axle and give a parallel lift to the frame. 
Biddell’s Cultivator, imtentecl in 1843, had separate lever 
lifts, one for the leading, and one for the rear wheels. Only the 
fii’st was used for turning in, and both together for travelling, 
but the arrangement was rather heavy and cumbersome. 
All these implements, however, may now be said to 
belong to history, and it is to be remarked that the cultivator 
attracted more attention from the farmer twenty-five years ago 
than it does at the present time. In demonstrating the enormous 
shattering power of the grubber, when moving quickly through 
the soil, steam traction has itself done a great deal towards 
discouraging the use of this implement in connection with horse- 
])ower. 
