The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-05-01
SCIENCE AND ART,


WHAT is GoLD LAcE.-Gold lace is not gold lace.
1t does not deserve this title for the gold is APP
piled as "A surface to silver. 1t is not silver
lace for the silver is applied to foundation of silk.
The silken threads for making this material are
wound round with cold wire so thicklv as to con-
ceal the silk; and the making of this gold wire is
one of the most singular mechanical operations
IMAGINABLE In tbe first place the retiner prepares
solid rod of silver about an men IN thickness ne
heats this rod applies upon the surface coating OF
gold leaf Furnishes this down. applies another coat
ing Furnishes this down, and on, until the gold
is about one-hundredth part the thickness of the
silver Then the rod is subjected to train of pro
cesses which brings 1T down to the state OF fine
wire, it is passed through holes in steel plate,
lessening step by step in diameter. The gold never
deserts the silver. but adheres closely to it, and
shares all its mutations it is onehundredth part the
thickness of the silver at the beginning, audit main
tains the ratio to the end. As to the thinness
to which the gold coated rod of silver can be
brought, the limit depends on the delicacv of hui
man skill; but the most remarkable example ever
known brought forward by Dr. Wollaston.
This an example of solid gold wire without any
silver. lie procured a small rod of silver bored
hole through it from end to end and inserted in
this hole the smallest gold wire he could procure
he subjected the silver to the usual wire-drawing
process, until he had brought it to the finest attain
able state--beno in fact a silver wire as fine as n
hair, with a gold wire in its centre TO isolate
this gold wire he subjected it to warm nitrous acid
by which the silver was dissolved leaving a gold
wire one-thirtv tbousondtb of on inch in fb;ct nes
man has vet produced But this wire thouoh be-
yond all comparison finer than any employed in
manufactures, does not approach in thinncss the
film Of gold on the surface of silver in cold lace II
has been calculated that the GOLD on the very finest
silver wire for gold lace is not more than onethird
of millionth of an inch in thickness: that is,
not above onetenth the thickness of ordinary leaf
gold.
Woxnrps or THE C,rc,-, ,rruc u.cr,>,r Al
though Dr. ndnn - En-
mechanism, it occupied twentv-five naces in Thy
Edinburgh Review for him TO describe The act;or ~
the calculating machine. and there wara so,oa Gao
lures which he gave up altogether as homeless VIII
out mass of diagrams which nobody would look al
but practical men Some of the onnoratus and
modes of action are indeed extraordinarv-nonr
than that for ensurinr accuracy in the cal
culated results If the machine does its work lii
tie in error it is rubbed info GOOD conduct nv The
friction of adjacent mechanism on the principle Of
sympathy which makes pendulums yibrate alike. but
ifthe machine works wrong, the wheels become
locked and refused to rotate They will nrorresc
rightly or not at all The first term of The tobIa
and the first term of each order of differences being
EVEN tne wh9e table can be constructed from these
bana pelng mace 10 lndlcate these num-
go; nI are L nm vi uiiis 10 represent Tue sue
A. n; VI lenHes, anu rows 10 represent
nrdinar oiSS a.s III q uil n anu ny an extra
b;nh ihoSn d;ni VI Hechaiisih, 'ile MleeIS 70
M'lOn lnese uias are attacneo act upon eacl other
T GiIeL ny the Original adjustment,
80 oi"i naS vi i's cuSes 'iie SCI Vi uiSils from
- T ri ,u, .-,..,. -, ,.,,- ~,
70 tho ,bae, hoL;d w.. AL tib eet
800 oDI a'le ai, not 'tIn aeI On OF
shouiders bioh rat ta nt;a - tt H. anu
AZ tnnth nrhnoi IN -; Jt; - "a a., wy o' ii
Addition Tben tbaro aro aoha. booI vi
dials, claws which catch in tha teoth of t"sn o.
etS bonlS hnb fasta ~ ,ae Vi 1nese
ooN i m" i iten VI ulasten the Claws spiral
fpta,S5od " t;a ut"M DIcN lle cihws when I'M
80. thhs miil0 seI 'ne HOURS III ac
etors nd Gs vi s.uus which govern the ing
go t %Lao IN .ne reF1lvlhs axies Which
IL -, ihEte ar ,iso snaii pieces on
n Ae Ui sonie vi inc Wheeis; levers TO De acted
upon ny 'n1se pieces 10 Ten aliereht hel9hts, ac.
epus 10 'e numerals; sectors at the other ends OF
tne lg'ers; zen punches IN each sector, having the
h earacler OF 'he Ten numerals; bent lever
s;t; mcoS upon particular punGn IN particular
position OF the sector; copper plate on which the