THE YOUNG 
be j^iven of the standard colors, or those 
in regular use, and ordinarily procurable ; 
of their mutual behavior in mixtures, and 
of the manner in which composite tints 
generally may best be obtained, and with 
this information in hand work in colors 
will be commenced. 
6. Porcelain and its Glazes.— In order 
that greater discrimination may be exer- 
cised in subsequent operations, it is de- 
sirable that the nature of porcelain and 
its glazes should be understood. I do 
not propose to give a history of pottery, 
or a detailed descriptioQ of tlie processes 
employed in the production of that beau- 
tiful ware now so easily and cheaply ob- 
tainable. Such a course would serve no 
useful pur[)Ose. A section on the subject 
would be highly interesting, but the 
greater portion of the information it 
would afford would be of no practical 
avail, and complete descriptions are 
readily attainable in public libraries, and 
are more fittingly found in the pages of 
an encyclopasdia, or a Dictionary of Art 
or Manufactures, than in a paper of such 
a series as this, the main object of which 
is the satisfaction of the wants of the 
practical amateur painter. It is, how- 
ever, essential that the painter who is de- 
sirous of attaining something more than 
mere mediocrity in his art, should be 
possessed of correct information respect- 
ing the two particulars to which I have 
just referred, as without this knowledge 
it is very probable that he will fail— how- 
ever well he may have worked — to realize 
his ideal, seeing that similar work exe- 
cuted with equal care upon two glazes of 
different descriptions may produce re- 
sults so entirely different, that in one 
case the liveliest satisfaction may be ex- 
perienced, in the other the keenest disap- 
pointment. 
Porcelain, then, is of three kinds, tech- 
nically known as Hard, English, and Soft, 
the last being also called tender, or spuri- 
ous, and tbe first also genuine. 
(a.) Hard Porcelain.— The body of hard 
porcelain is essentially composed of two 
substances, both of which occur natur- 
ally: 1. Kaolin, or as it is sometimes 
called, China clay, an argillaceous earth, 
the most valuable beds of which have 
been found in China and Japan, in Sax- 
ony, in France near Limoges and near 
Bayonne, and in England in Devon and 
Cornwall— the English variety resembling 
the Chinese and Japanese rather than the 
Continental. 2. China stone, a quartzose 
felspar, here called "crockery stone." 
These two substances occur in the form- 
ation called "graphic granite," but 
whether tliey have resulted from the de- 
composition of the granite, a further stage 
having been reached in the case of the for- 
mer than in that of the hitter, or whether 
they are constituents of imperfectly 
SCIENTIST. 147' 
formed granite, the latter being more de- 
veloped than the former, is not yet deter* 
mined. Their origin is, however, notice- 
able, as they are causative of the hard- 
ness of the ware. By whatever means 
brought about, the important point is 
that the stone contains a large portion of 
alkaline matter, but little of which exists 
in the clay, and is accordingly fusible, or 
capable of being reduced to a molten 
mass, while the clay is infusible, or under 
heat retains its earthy character, and be- 
comes of a brilliant opaque whiteness. 
The stone thus acts as a flux to the clay, 
and it is to this flux that nearly all hard 
porcelain owes its translucency. 
The principal seats of this manufacture 
are the district round Limoges and 
Sevres. Hardware is also made in dis- 
tricts bordering on the Rhine (Sarregue- 
mines, Saarlouis, Vaudrevange, Mett- 
lach, Maastricht), at Meissen (Dresden), 
Berlin, Vienna, St. Petersburg, etc. The 
Chinese and Japanese ware also belongs 
to this class. In England hard porcelain 
was first made by Cookworthy at Ply- 
mouth (a.d. 1760), subsequently at Bristol, 
and later at some of the Staffordshire 
works. 
(To he continued.) 
Amateur Boat-Building— l 
N order to prevent any miscon- 
ception as to the scope or object 
of the "Hints on Boat-Build- 
I ing," which we purpose to offer 
in tlie pages of the Young Scientist, a few 
words of introduction may be expedient. 
In the first place, then, the " Hints " 
are not intended for the instruction of 
professional boat-builders. They are, on 
the contrary, mainly addressed to the 
large and increasing class of amateurs 
who desire to build their own " boat " at 
small expense. The instructions con- 
veyed will, therefore, necessarily be of an 
elementary character, and the general 
style of the papers somewhat discursive. 
Secondly, it mUst be distinctly under- 
stood that in describing any particular 
manner of performing an operation, or 
recommending any special style, we shall 
not mean that such are the only ones— 
nor, indeed, necessarily the best. They 
will be simply those which commend 
themselves to us, and may, perhaps, in 
many cases be taken as hints for the in- 
genuity of our readers to improve upon. 
In sta.rting, let us briefly describe the 
more usual forms of boats used on rivers. 
The simplest form of boat may be taken 
to be the flat-bottomed, square-ended 
concern known as a " punt," and much in 
use for angling purposes. This form of 
boat is very safe, and is capable of going 
up shallow and weedy or muddy streams, 
where it would be impossible to get any- 
