THE YOUNG 
us across the Fire Hole Eiver, we as- 
cended a gentle incrusted slope, and came 
suddenly upon a large oval aperture with 
scalloped edges, the diameters of which 
were 18 and 25 feet, the sides corrugated 
and covered with a grayish-white silicious 
deposit, which was distinctly visible at the 
depth of 100 feet below the surface. No 
water could be discovered, but we could 
distinctly hear it gurgling and boiling at 
a great distance below. Suddenly it be- 
gan to rise, boiling and spluttering, and 
sending out huge masses of steam, caus- 
ing a general stampede of our company, 
driving us some distance from our point 
of observation. When within about forty 
feet of the surface it became stationary, 
and we returned to look upon it. It was 
foaming and surging at a terrible rate, 
occasionally emitting small jets of hot 
water nearly to the mouth of the orifice. 
All at once it seemed seized with a fearful 
spasm, and rose with incredible rapidity, 
hardly affording us time to flee to a safe 
distance, when it burst from the orifice 
with terrific momentum, rising in a 
column the full size of this immense aper- 
ture to the height of 60 feet ; and through 
and out of the apex of this vast aqueous 
mass, five or six lesser jets or round 
columns of water, varying in size from six 
to fifteen inches in diameter, were i)ro- 
jected to the marvellous height of 250 
feet." 
The Great Geyser, as shown in the illus- 
tration on the preceding page, differs from 
the Giantess, in that its action is more 
violent. With scarcely any preliminary 
warning, a volume of hot water, eight 
feet in diameter, is thrown up to the as- 
tonishing height of 200 feet. So steady 
and uniform does the force act, that the 
column of water appears to be held in 
place for some minutes. This violent ac- 
tion takes place at regular intervals of 
about thirty-two hours. 
Ornamental Turning. 
nnO the novice in ornamental turning, 
the more simple the apparatus to 
commence with the better, and it will be 
advisable not to have too much in the 
shape of instruments to begin with; if 
this is the case, they all come in for a 
SCIENTIST. 109 
small share of patronage, and little or 
nothing is done with any. In order to give 
the tyro some idea of the best means of 
fitting up a workshop, and using its con- 
tents, we propose detailing here the neces- 
sary items to commence with, First, then, 
we must have as a groundwork, a good 
lathe, and the one we recommend will be a 
5-inch centre, with a traversing mandrel. 
This is not absolutely necessary, because, 
by practice, it is not a very difQcult pro- 
cess to cut a screw without its aid, but as 
there are times when its use will save a 
deal of trouble, we certainly advise it. 
As an instance of its use, take the lid of a 
snuff-box, which is so short as a rule that 
it becomes a very difficult matter to in- 
sure a true thread, and as blackwood and 
ivory are so expensive, it is policy to save 
it at all risks. This, however, must re- 
main with the person who is about to in- 
vest his money in one of these interesting 
instruments, and from w^hat we have 
lately seen of their productions, it cannot 
be wondered at that so many are devoting 
their attention to it. Having obtained a 
lathe as described, if quite a novice, it is a 
great advantage to become efficient in 
plain turning before aspiring to the orna- 
mental branches. When sufficiently ex- 
pert in the use of the gouge and chisel, 
attention may be turned to the higher 
branches, and we have found that the 
best way to proceed is to first procure a 
good slide-rest fitted with a metal cradle 
and stops, to place the T of the slide to 
turn a true surface or cylinder. This is 
very essential, as it saves the trouble of 
adjusting the slide at each movement. 
An over-head-motion is now made with 
two cast-iron standards with triangular 
bar at the top, and a round bar with pullies 
on a drum. On it, revolving between two 
steel centre screws on the top bar, is fitted 
a carriage in metal, through which passes 
an iron bar with a cast-iron ball on the 
end, adjustable as to distance. This is to 
form a counterbalance to alter the tension 
of the band upon the various instruments. 
On the front end are two guide pullies to 
conduct the band to its position. The 
lathe now begins to assume the form of aji 
ornamental turning one ; a few more addi- 
tions, and we make a start— an eccentric 
