15G 
MAGAZINE OF SCIENCE AND ART. 
MARKHAM’S DIGGING MACHINE. 
At the meeting of the Horticultural So¬ 
ciety, held November 3, 1857, nis Excel¬ 
lency the Governor-General forwarded a 
model of a Digging Machine, constructed 
by Mr. Lewis Markham, of Armidale,— 
the same gentleman whose description of a 
Reaping Machine appears in this number 
of our Journal. According to the promise 
made in our last number, we now give the 
inventor’s own description of the machine. 
Permit me to offer to your notice the model of 
a digging m,.chine, constructed for the purpose of 
working cultivated land in general, hut more es¬ 
pecially alluvial soils. It is built on the principle 
of a vertical saw mill, with double power on the 
downward stroke—that is to say, the power is em. 
ployed in propelling the machine and lilting the 
spades, which are supposed to he sufficiently 
weighted as that by their fall they shall penetrate 
the soil, and are also levered out by the assistance 
of the machinery, hut principally by their own 
weight. 
Being conscious of the fact that doctors differ, I 
desire to give no opinion as to its probable success 
with animal power, hut with steam power I will 
venture to say that it could he brought to a state 
of perfection not to be surpassed by anything ever 
yet offered for the purpose for which it is intended, 
and in order that it may be better understood I 
will give its description on a large scale. 
Por a two-horse machine :—Length of frame, 11 
feet; the hind portion consists of a spade frame 7 
feet broad, 5 feet long, and ,1 feet high ; ihe breadth 
includes two broad wheels, to support the frame. 
The remainder of the machine is 4 feet broad aftl 
21 feet high. The spades are 5 in number, anTfl 
inches in depth, extending across the breadth of 
the inner space of the frame (3 feet). They are 
bolted to a handle 5 inches square and G feet long, 
and are propelled by a crank and fulcrum, the 
latter working in a slide, so as to admit of the 
spades rising and falling, and performing the work 
in a similar manner to a spade in the hands of a 
man, but without turning the sod. From the end 
of the spades to the fulcrum, H foot; from the 
fulcrum to the top of the handle, G feet.; depth of 
crank, 9 inches; two lly-wheels attached, 3 feet 
each in diameter ; motive power, 3 united wheels 
within the frame—the 2 outside wheels 5 feet in 
diameter, spiked, the centre wheel 41 feet in dia¬ 
meter, grooved, and carrying a belt which com¬ 
municates indirectly with the fly-wheels and spades. 
Weight above the spades, 200 lbs.; of fly wheels, 
150 lbs. each ; strain of horses, on the downward 
stroke, ifto lbs. This would give the spades a fall 
of 9 inches, with r. probable weight of 700 lbs. 
One revolution of the main wheel (15 feet), gives 
15 revolutions to the fly wheels, and the space dug 
would thus he 15 feet by 3. There are two small 
wheels iu front, which are placed for use in bring¬ 
ing the machine into the field ; they are then fas¬ 
tened up, free from interference with the action of 
the machine. 
Many may he anxious to know the result of the 
spades coming in contact with rock or stone. Sup¬ 
posing the spades set to dig any given depth, and 
that they come in contact with a substance which 
the weight described is not sufficient to cause them 
to penetrate, the machinery stops, and the whole 
weight of the machine is instantly brought to bear 
on the spades, and if the substance is still too hard, 
the spades, instead of penetrating, will lift the ma¬ 
chine, and so on till they come to softer soil. To 
adapt this machine to animal power was the great 
difficulty I had to contend with, as slowness of 
motion was only to be obtained from the greater 
diameter, while velocity was to be procured from 
the smaller, but any person who will look at the 
model of the machine will see that by removing 
the large wheels, bolting an engine on to the frame, 
bringing the piston directly in contact with the 
crank wheel that works the spades, and propelling 
the machine by the shaft of the fly wheels, that 
power for the cultivation of any description of soil 
might be given, and be equal to an almost incre¬ 
dible amount of work. 
LEWIS MARKHAM. 
Armidale, October IS, 1857. 
EXTRACTS. 
Photography. —Those of our readers who are 
amateurs in this popular brauch of Art, will derive 
much pleasure from an inspection of some remark¬ 
ably fine photographic portraits exhibited by Mi. 
T. S. Giaister, in Pitt-strcct. The peculiarity 
about them is their large size, being as nearly as 
possible life-size. They are Collodiotvpes. A sheet 
of glass, 17 inches by 22 inches, is evenly coated 
with a film of Collodion, upon which image is im¬ 
pressed. Mr. Giaister possesses some fine sped, 
mens. There is one of the Rev. \V. Cuthbertson, 
which surpasses all that we ever saw in portraiture. 
We may here remark, that numerous cases have 
come to’ our knowledge, in which portraits taken ly 
the various photographic artists in this city, and 
sent to England, have created astonishment there 
by their extraordinary beauty of manipulation. 
W r e have received assurances, front artists of repute 
at home, that the London photographers are quite 
eclipsed by our Sydney practit ioners. By them the 
superiority of photographs done here (we allude 
only to collodiotypes) is ascribed to the influence 
of the climate, and it is reasonable to suppose that 
the superior intensity of the sun's rays should have 
given us an advantage over those taken beneath the 
sickly sun that has to force its way through a 
murky London atmosphere. At all events, Messrs. 
Dalton, Freeman, or Giaister have nothing to fear 
by' comparison with any' English photographic ar¬ 
tists. AVe hope to see a Photographic Exhibition 
in Sydney before long. It would be very attrac¬ 
tive. 
Edible Nests of Swallows. —M. Huten, 
chief physician of the Invalides at Paris, states that 
these nests, collected in Java, are considered by 
the inhabitants as formed from fish spawn. The 
viscid filaments often seen hanging from the bills 
of the birds are said to be derived from the spawn. 
Errata. —-In November number—in the paper 
on “ Silurian Fossils,” p. 136, column 2, for " pai- 
rallel,” read -parallel; tor “ Blumanbachii,” read 
Blumenbachii ; for“Yarrulumla,” read Yarralumh. 
