THE YOUNG SCIENTIST. 
3 
; Nos. 3 and 4 are wires, bent, as shown in the 
figures, and hound firmly upon wooden han- 
dles ; they are used to pick and dig with. 
You will want, at least, two sizes of each 
kind, and besides them, a pair of dividers and 
a pair of calipers. The dividers or compasses 
are well known; the calipers must be large, 
and capable of being fixed at any distance 
apart by means of a set screw. The best form 
of this tool is drawn in Fig. 2. They sheuld 
be ,at least a foot long. Those will be all 
the tools you will need for the clay, though 
you will see a greater variety at the image- 
makers. 
I Many persons suppose that the ''Image- 
i makers," as they are called, design the images 
they cast in plaster. That is a great mis- 
take : very few, if any of them, do so. They 
\ are designed in clay first by artists ; the clay 
model is then covered by a plaster piece-mould 
by the plaster worker, who can turn out a great 
number of " copies " in plaster from one mould 
before it is worn out. The artist usually gets 
a percentage on every copy sold, and some- 
times, when an image is "something striking," 
it proves very remunerative both to the artist 
and the caster. 
Nearly all the artists understand the art of 
casting, but all aeem to dislike working in 
plaster. You will be able to judge whether 
you will like it or not before you have finished 
this series. 
The next day you can begin to take meas- 
ures for the profile, which is always the first 
thing to be done in bust-modelling. 
Unless you have a very true eye for outlines 
you will have to go by measurements almost 
entirely, and in order to have a point on your 
clay that you can measure from in every direc- 
tion, you must first find the distance between 
the two ears of the sitter with your calipers, 
by placing the points on the fleshy knobs at 
the entrance of both ears ; be very sure that 
the points just touch the flesh on both sides, 
but do not press it in, then screw up the cali- 
pers and you have your first measurement, 
which you will make use of in the following 
manner. 
Suppose Fig. 2 represents the mass of clay 
as you built it up ; it is, at least at the top, 
twelve inches thick ; while, by placing the 
points of the calipers on a rule you find the 
sitter measures from ear^to ear only, say, five 
and one-half inches. 
Take the calipers, screwed up as they are, 
and mark with them two lines down the mid- 
dle of the clay as represented in the cut, about 
as long as the face is to be, then make the dot 
between them, which will be where the end of 
the nose is to come. 
Now, with the calipers measure the sitter 
from the end of the nose to the knob at the 
entrance of one ear. Take a large knife and 
cut away the clay carefully from both of the 
Fig. 3. 
straight lines, as shown by the dotted lines in 
Fig. 1, until you can get both measurements on 
the clay — from ear to ear, and from the end of 
the nose to each ear. 
If the face of the sitter is very full, so that 
the distance across any part of it measures 
more than the distance from ear to ear, you 
must allow for the fullness, as shown in Fig. 
3, by rounding out the clay beyond the straight 
lines, instead of cutting it down even with them. 
In order to get the screwed up calipers back 
