THE YOUNG SCIENTIST. 
In practical business, half-a-dozen or 
moie stamps are matle at one operation, 
tlie wording of each being arranged as 
required, and the types put into tlie chase 
alongside of one another, so tliat name 
stamps, ovals, square stamps, and round 
will be next-door neighbors. A. plaster- 
cast is then taken in the usual manner, 
as if only one stamp were being made, 
and a similar cast in india-rubber; the 
various stamps are then cut and sepa- 
rated from one another with a pair of 
scissors. 
. • . 
Overglaze Painting on Porcelain— III. 
BY AUEELIO DE VEGA. 
N purchasing brushes to operate 
with, some care is necessary, 
and the following hints will 
doubtless be of service : 
18. Testing Brushes. — Whatever kind 
may be selected, the best only of that 
kind should be used. It is impossible to | 
produce a highly-linislied work with bad j 
tools. In a good brush, when dry, the 
body is perfectly elastic, and the hairs 
liave a i)erfect spring, and lie equally 
together. 
A brush should not be purchased with- 
out having been tested. Always test your 
brushes in water. If the seller does not 
proffer the jar of water, ask for it ; if he 
does not produce it, do not buy. The 
water forthcoming, di[) the hairs in it so 
that they become fully charged. Then 
holding the handle tightly between the 
ends of the thumb and second linger, sud- 
denly dei)ress the latter, retaining the 
brush between the thumb and tlie first 
linger. This jerk will send off the super- 
fluous water, and then the brush, if good, 
will at its end present, if a round or small 
flat one, a fine point, if a, large flat one, a 
fine, straight, or slighl ly-curved line, to 
which, in either case, the body has regn- 
Inr'ly decreased. If a round brush should, 
after this test, have protruding hairs in 
1 lie body, or free hairs at the end, or a 
Hat one have some parts of its line 
thicker than others or depressed, or the 
terminating i^oint or line be not led up to 
gradually, reject it without further con- 
sideration ; it is not a good brush. 
19. A common test is to moisten the 
brush slightly in the mouth, and draw 
the hairs together through the lips. This 
is a procedure giving most uncertain re- 
sults, not to mention an obvious objec- 
tion to it. In a brush not absolutely 
worthless, but a long way' from being 
thoroughly useful, the stickiness commu- 
nicated by the saliva would impart to the 
hair-tips a. certain ainount of cohesion, 
causing a point which under the proper 
test would never form. 
20. One further caution is necessary, 
and is addressed rather to those living in 
the country. It may be that a piece of 
work is in hand which it is desired 1o 
finish quickly, but through some accident 
the suitable brushes have become 'useless. 
For convenience, application for new 
brushes is made at the nearest shoi:» pro- 
fessing to sell artists' materials. Now, 
a good many of the small and pretty nu- 
merous shops which make this profession 
act up to it, and at them serviceable tools 
may be obtained ; but others, ^ am sorry 
to say, do not, and a,t these one may meet 
with brushes already presenting a very 
good point, which, alas! is more fre- 
quently than not the result of the addi- 
tion of a little mucilage to the water 
with which the hairs have been moist- 
ened. In this case the hairs are a trifle 
harsh and stiff. If you cannot conveni- 
ently search elsewliere, rub the brush 
between ilie fingers to remove the pow- 
der, and test with water as above sug- 
gested. A good one may possibly be 
found among the lot. 
21. The Shape and Size of the Brvsh to 
he employed. — These particulars will de- 
pend upon the nature of the work and 
the extent of the surface to be covered, 
and hence there is great variety in these 
respects. 
22. Skies, Water, and Grounding.— Fot 
skies, and water in which there is a, pretty 
large slieet of color, either of one intensity 
or graduated, and to be left as laid, or to 
have the clouds or lights picked out, a 
flat brush, as shown in Fig. 4, is generally 
about the best; but in smaller or some- 
wha.t irregular work', that showm in Fig. 5, 
which is often called a sky brash, is per- 
haps most serviceable. The size should 
be such as to allow of enough paint being 
