CLA 
him even the letters of the alphabet on the 
figures of Euclid’s Elements, by which he 
was able to read and wTite at four years of 
age. By a similar stratagem' it was that 
calculations were rendered familiar to him. 
At nine years of age he put into his hands 
Guisn^e’s Application of Algebra to Geo- 
metry ; at ten he studied THospital's Conic 
Sections; and between twelve and thirteen 
he read a memoir to the Academy of Scien- 
ces concerning four new geometrical curves 
of his own invention. About tlie same time 
he laid the first foundation ofhis work upon 
curves that have a double curvature, which 
he finished in 17'29, at sixteen years of age. 
He was named Adjoint-Mechanician to the 
Academy in 1731, at the age of eighteen, 
Associate in 1733, and Pensioner in 1738. 
During his connection with the Academy he 
had a great multitude of leai'ned and ingeni- 
ous communications inserted in their me- 
moirs, besides several other works which he 
published separately. In the year 1760, the 
Academy of Petersburgh proposed a prize 
on the subject of the lunar motions, which 
Clairault obtained : and in a few years he 
obtained another prize on the same subject. 
He was during life a most active and inde- 
fatigable man. He died in 1765, at the age 
of 52. His works are numerous, and his 
papers, inserted in the memoirs of the aca- 
demy , may be found in the year 1727, and also 
for almost every year till 1762 ; being upon 
a variety of subjects, astronomical, mathe- 
matical, optical, &c. 
CLAMP in a ship, denotes a piece of 
timber applied to a mast or yard, to prevent 
the wood from bursting ; and also a thick 
plank lying fore and aft under the beams 
of the first orlop, or second deck, and is the 
same that the rising timbers are to the deck. 
Clamp is likewise the term for a pile of 
unbumt bricks built up for burning. These 
clamps are built much after the same man- 
ner as arches are built in kilns, viz. with a 
vacuity betwixt each brick’s breadth for 
the fire to ascend by; but with this dif- 
ference, that instead of arching, they 
truss over, or over span ; that is, the end 
of one brick is laid about half way over the 
end of another, and so till both sides meet 
within half a brick’s length, and then a 
bindin;:, brick at the top finishes the arch. 
Clamp nails, such nails as are used to 
fasten on clamps in the building or repairing 
of ships. 
CLAN, a term used in Scotland to de- 
note a number of families of the same name, 
under a feudal chief, who protected them, 
and, in return for that protection, com- 
CLA 
manded their sei-vices as his followers, and 
led tliem to war, and on military excursions. 
CLAP net, a device for catching larks. 
You entice the birds with calls, and when 
they are within your distance, you pull a 
cord, and your net flies up and claps over 
them. 
CLARIFICATION, is the separation, 
by chemical means, of any liquid from sub- 
stances suspended in it, and rendering it 
turbid. If a diflFerence can be made be- 
tween clarification and filtration, it is, that 
the latter is effected by mere mechanical 
means, but the former either by heat or by 
certain additions, the action of which may 
be considered as chiefly chemical. The li- 
quors subjected to clarification are almost 
without exception those animal or vege- 
table juices, in which the matter that ren- 
ders them turbid is so nearly of the same 
specific gravity with the liquor itself, that 
mere rest will not effect a separation. In 
these too the liquid is generally rendered 
thicker than usual by holding in solution 
much mucilage, which further entangles the 
turbid matter, and prevents it from sink- 
ing. Hence it is that vinous fermentation 
has so powerful an effect as a clarifier, since 
this process always implies the destrnction 
of a portion of saccharine mucilage, and the 
consequent production of a thin limpid spirit. 
Coagulating substances are great clari- 
fiers when mixed with any turbid liquor, 
the process of coagulation entangling with 
it all matters merely suspended and not dis- 
solved, and carrying them either to the top 
in the form of a scum, or to the bottom in 
the form of a thick sediment, according to 
circumstances. Thus, to clarify muddy 
cider, the liquor is beaten up with a small 
quantity of fresh bullock’s blood, and suf- 
fered to stand at rest for some hours, after 
which the liquor above is as clear as water, 
and almost as colourless, and at the bottom 
is a thick tough cake, consisting of the co- 
agulated blood which has carried down with 
it all the opaque matter suspended in the 
liquor. Albuminous and gelatinous sub- 
stances act in the same manner. The ef- 
fect of white of egg in this way is known to 
every one. It should be first mixed with 
the turbid liquor, without heat and by agi- 
tation. Afterwards, on applying less than 
a boiling heat, the albumen of the egg co- 
agulates, and carries up with it all the 
opaque particles, leaving the rest beauti- 
fully clear and limpid. Sometimes clarifi- 
cation takes place in a very uiiaccountable 
manner. Thus, it is well known, that a 
handful of marl or clay will clarify a large 
