annel from 25 to 35 feet wide, and deposits
all the dirt upon one side. If necessary, it can dump earth about 25 feet
above the track. The miners follow in the wake of the machine, getting out
the phosphate as fast as it is uncovered. When the machine reaches the end
of the field it is lowered to the track and the screw-jacks are removed.
Shoes or skids are then placed upon the track, and the wheels of the
turntable are run up on them. This lifts the end wheels clear of the
track, so that the car and machine rest entirely upon the turntable. By
now blocking the turntable wheels and winding up only _one_ of the ropes,
the car body and the machine are swung around end for end. The digging is
then resumed in the opposite direction, the temporary track, upon which
the machine travels, being shifted to one side, so that the second channel
is made alongside of the first. The earth removed in cutting this second
channel is dumped into the first channel, the phosphate (as stated above)
having been first removed.

The dipper is of plate steel, and holds 13/4 cubic yards of earth when even
full.

The machine is manned by an engineer, a fireman, and a dipper-tender,
besides which from five to ten laborers are required. These look after the
track, etc.

* * * * *

CAPSTAN NAVIGATION ON THE VOLGA.

On several of the large rivers on the Continent, with rapid currents,
cable towage has been introduced in addition to the older methods of
transporting merchandise by sailing and steam boats or by towage with
screw or paddle tugs. A chain or wire rope is laid on the bottom of the
river bed, fixed to anchors at the ends and passed over a chain pulley
driven by the steam engine and guided by pulleys on the steam tug, the tug
lifting it out of the water at the bow and dropping it over the stern and
winding itself with the barges attached to it along the chain, the latter
being utilized as a rule only for the up journey, while down the river the
tugs are propelled by paddles or screws, and can tow a sufficient number
of barges with the assistance of the current. The system has been found
advantageous, as, although the power required for drawing the barges and
tugs against the current is of course the same in all cases, the slip and
waste of power by screws and paddles is avoided. The size of the screws or
paddles is also limited by the nature of the river and its traffic, and
with cable towage a lar