to the Cultivation of the Land. 
187 
travelling from place to place. The two 8-inch steam-cjlinders 
(of 16-inch stroke) are placed underneath the smoke-box, like 
those of railway locomotives, and are fitted with reversing motion. 
The front pair of wheels are hung upon castors, the steerage being 
effected by controlling their swivel motion, or when turning short 
round with one of the large carriage-wheels as a centre, they are 
set entirely free to roll themselves in any direction. Screws, 
upon their supporting stems, are provided for adjusting the level 
of the boiler to inclinations of ground surface ; and there is also a 
balance-beam connecting these stems, for dividing the weight 
equally upon each wheel, and allowing them to accommodate 
themselves to uneven land. The digger in its lever-frame is free 
to play up and down, according to the hollows or protuberances 
of the field, a small wheel at the end next the untilled land 
regulating the depth against fluctuations in the posture of the 
machine, so that, while the digger breaks or cuts up bricks, roots, 
&c., without injury, it rises over a very hard or immovable im- 
pediment, its weight being about 7 cwt. To lift it out of 
work, two hydraulic cylinders are provided, one on each side 
of the fore part of the machine, and steam being admitted, forces 
the pistons along the cylinders, and by means of chains pulls up 
the frame to the required height. Water is proposed to be used 
in place of the steam, which does net operate steadily or under 
such accurate control. The whole machine is about 18 feet in 
length and 10 feet wide, and weighs about 12 tons. 
I saw it last November, at Royston in Cambridgeshire, working 
on a piece of mown stubble — a light, chalky, turnip soil, of a 
quality that turns sticky with wet, but dry and friable at that time. 
The main wheels of G^- feet in diameter, made witli T iron spokes 
and plate-iron felloes 21 inches broad, sunk very considerably 
into this land, plainly showing the necessity for having flat plat- 
forms like those of the "endless railway" over which the heavily- 
weighted wheels might roll, but the difTiculty of turning short 
round upon these "shoes" appears to be hardly overcome at 
present. The shares or cutters were arranged three in a row or 
ring, three successive cuts being made in one revolution of the 
cylinder, and, the advance for each cut being about 6 inches. 
The digger made between 30 and 40 revolutions per minute, 
the engine running at from 120 to 160 strokes per minute, 
varying according to slight elevations and depressions in the 
ground. 
The earth was well subdivided by the 33 cutters (that is 11 
rows), and turned up in small spits, beautifully broken, much like 
spade work ; the depth not exceeding 6 inches, or rather 6 inches at 
one end of the digger and 4 inches at the other, owing to want of 
rigidity in the lever framing. This it is proposed to remedy by 
