, 1865-07-10
A Day Of Small things NOT to be des'
Passd.The mode Of meAsurln& mans
nte maKAltudea.


iii produce fiat surtace, and how to measnn
At small distances md quantities accurately. In
q. plain dat aur1ace Of iron or steel which uset
10 to satisfy engineers q few yea.s sgo, wonlt
j, now be REGARDED as alterDAtions Of ridges
i, grooves, lnmps and holes; While the thick
" " ness Of wtres plates and sheets which couls
y once be measured to the hundrath OF an Incl
! or 60, can now be measured by-But lei
ID us explain this matter little.
T. When VIC turn q screw once round, In nul
CT hole fitted to receive It, We at the samt
time push 1t forward to distance equal to
one thread Of the screw consequently, II the
screw be turned only one tenth round, It ad'
vanccs only one tenth Of the distatce BE-
ly, again, If there were hundred threads
TO the inch, md the screw were turned onlE
one hundreth part Of q circumference, y
would advance only one ten thous1ndth part
|, Of an inch forWnrd. All this Is well ikno wn
to persons accustomed to tools and machine
showing how to attain the actual result In 4
degree hardly conceivable. a few years ago,
. ] he eontrived an apparatus which Touid detect
; the difference between the length OF two baEs,
part of an inch! There was a SCREW with
len threads to an inch there was tangent
) screw wheel with 100 teeth In Its circnn-
ference, G1d q graduated circle With $50 dlyis-
ions these parts were so connected that =
) movement equal to ono division of the circle
! ls. equal to an n1rnuce Of the ectcW through
epac, Of only one milliouth Of an inch. The
mlcIometer was paced at one end OF q frame,
on which the bar to be measured was tempo.
ralily placed. Whepa small piece OF metal
with its opposite eustaee parai]el, and e1.
quisiteIy true, Is PLACED between the bar and
n!lcrometeE, the latter Is sclewed IN until
the email piece Of metal (called thu contact.
plece, y lust nipped an6held between them
then II the scteW be brought back rucrely
one.millionth Of an inch, he contackpIece
is ioosencd and FALLS Although the
| eyedoes not detect It, the n,ch1ne does YER
itably measure this hanitcsimal quantity,
A A. ,s su Ensrson !; Tsnnent sayst in bis: Story
Of ne Guns: "so nice Is tte adjustment
that, in using 1t, nj inch Of steel csn bcheld
to be an Inch cnly 60 long IS the rietrmome-
ter stands st g. degrees Fahr=n tho
slightest excess Of temperature producinGau
/, appreciabie e1engatior. And the stan6ard ]
i yard, sauaFe bar Of steel, when pla6ed n.
touch Of the fuGcJ, as to show an appteclabl<
lengthening even under The influence Of the |,
iuansteslmal' a1lount Of heat thus impaired! ]
Mr. Whttworth, like other Inventors; ms +
contnEances as these; but bis profit begins
when be applies the same principle n hts |
workshop to produce articles In general d.
mand.' Ihe result rs ssen In many Ways.
working metal to one:tusntieth Of an inch:
but the one-thousandsh R IN Inch ia now
worked ns accurately sa the onn-tweatiesh
was tleni In making the exquisite details
ofthe WhitwoEth ziEh Or "a shaping aud adt
have come to rfEari tue ten -thousandsh part
Of an inch (one-hrndrctth th pert Of eRe-hun~ Fl
dleth OF an iuch} as quantit3 wittan their Ii
eogntzance, and On ~htch rhelr creslit a,
soed workmen may depend. In the eouraz
sgonal bores, conoidal talletB, md 30 forth,
Dir. Wht1wofth made cylinder 95770 inches !
internal diameter, rod 0'5%70 Inches
thick and another rob 0s409 'lnshes thick; !
tho cne rod fltted tightly into the cylinder !
~hen both were clean and dry; the other :
rod passed quite loosely ,intoit; and yet sbo
two reds differed In thickness only by the 4 ?
tcn-thonsandth part Of an inch: n ahost,
- little" to the 1aet generation; wauid, ~ :
pr p'estnt mcchactctans, BE- easily divided E
To produce minute results, fnstead Of mere-t
y measuring them VIXEN produced BY cthess.
i the purpose Of many heautffut eontrIpanc.s
PhotogIaphy is now ore of the oSsnte for e1 J
fecttng this. There arc. little Photographic
pictures, not larger than pins head, con-
tanning mnltituats Of portraits OF d!s.tu~
Kusshed persons; fo.:allz1ng RppfEatns pro- b
deee them, and microscope Is necessary to y
render them visible. p
At Tbs great Intern ational Exhibition of Il
1861 many persons Ela need at the beautiful r.
machins const1uoted'by III. !
Peters. the london ban keT; but the glance b
told little, except to ,hoGe who wese pre- }
7ious!y somewhat we're ed In the subject. d
Most attractive were thts wonderful bits OF e
writing on glaae which b I'd been effected BY =
the machine and which corN only be sea- =
,efed Visible By the aid ot powerful miesos. i
'eteuce, Invented ths machl ne. and soma tins u
fterwa'dap1eteuted IT to the Mlcroscopial
society, " whom It was Exhibited at the !,
'reat International gatherIn z. Suppose that !.
metal bar .s saspe endrd yer t!cally. By ful. 4
:rum or lto'ds exactly IN til !: ntlddle; Il the i
,aE ia swung to and fio, the op will descsibe a
! yulve exactly Ike, In size Anelorm, .that =
described 4. " the lower end, b u opposite IN
llstant fiosa-the fulcru1n as Ii upper, and If \
he bar be awung to mud fro, be lower end E
I'LL describe curve or arc lust twice as loov |
= I, thai - dssesloe4 By the upper. though sim. I
lar IN shape; y. on thu otbe lksad,. ths 7
han the upper, and IL the rati Of distancrs !
1e {sayj ten 10 .une, then the up per end viii I =,
letct1oe ns. asc ten times as ] arge as tha \
over, thsash Of course revert Cd in dirac- >
lon And 80 on In any other alto. Now. u
Ct there esl q blunt tracer at ono end OF the :.
'ar, and q 1enc Ant the other; IL we watex or =,
lrn#, o. Trace any fgnre TttR tht: tracer, xhe
,t1cs @ss BE- made to ths dguss on
lcarer totne tulc1un than tha pencil, d. +
n.ntsbed u otherwise. Here VT, haps tha g !.
lrst germ OF Mr. Peters mk roeaph; a ifaa
EIitsng = nodGt.tssiy :ssed eha racers, re, q
If pantngFaph. In the first mac Fins which Y
le made,- the fnlcrum WRs h1tndIed. and %
tlE1es nearer to one end Of thu r. r.
bar thaa to. the other aau tbs penEEc3py ~
.ize, But uotaele as was this posler Of dlu1- u
mutton, Mr. Peters hit upon att expRdiens | tu
That enabled him to eclipse It In an aston IN
shiug degree Instead of clustng the;short o. ..
,raver, he caused 1t 70 move the long azn Of VI
,nothsr but much smaller lever thus OBJ
tanning the product Of two dimlnutlons u1l- IA
liplted Into each other, instead Of the DIM "a
I ution duo TO simple lever: La h!s, large y
lever, he made the fulcrum l25 times nearer H. IL
10 the thort than to the long end, ,h his ii
smaller, the ratio WAS 50 to i, aud "a the | Be-
ehozt arm OF the first acted upon the long | ~
arm Of The second. the two ratios wcre mul. e e
1Plied, inaomnSh that he opy-Tftting was ~ ~
Suppose, for example, that the tracer ruled III
parallel lines one-tenth af an Inch apart, then
he pt neil would rule lines 1-Ga,D ,DOih Of au 70
inch apart; aud any writing, drawng, or de- u
next achievement Ut NJ. Peters Was so 10 ca ca
construct tbs exquisite details, Of his ma 81
chine that he could vary the power Of dim ID
but1on at pleasure, from Q ratio Of to he
10 up to = ratio Of 70 COD. Consider b b.
ninnte'y approximate lines on paper, he en- ~ u;
oloye1 diamond to se1atch on glass. The bits "
y diamond called "su.ned points" are found 10
latter for this purpose than "tplfnters." The 10
opg end of the lever, Whigt, Is downwards. | on
:ar5iss tracer, with which any design Of 60
Fliting ia traced. The upper end carries q 5o
mali p!ece Of glass, carefully adjusted over ~
10 glass Is mounted a diamond pointing en-
which remains stationary while th
sm is connected With the diamond, By 2.
NJ aps of which II may be aalood or lowe I'd, ol
I'd aiso pressed with g-*ater OF lees force M n,
n .uG ssI III 1h IT, s9 @ fLs theaa III