1000000031

454 / 868

E p 397
'by J. Nefe" baron ofM<r~hi(\on, in Seod and, where·
) N E p
c'p, city oi the ho:< b~ing d;"ided ' r,. o tm et lls for
the diÜl!rcnt fpecics of rods. \Vhen [he rc¿s are put
up in the hox fpecies in i.. own cdl di!ll ngllilhed
hy the GrCl figllre of the rod Ce, before it on the fjce
of the box ne.. the top) as much of el'cry rod (hnJ.
",ithont the hox as n,eW~ the fi,n figure of lhat rod ;
al fo "pon one of the nat lides withou, ood neH the
edge, "pon the ,lef, hand, the ind rx rod is fixed ; and
along the foot there is a fmall ' ledgc, fo that 11" rod.
\Vhen applied are laid upon this fid e, and fupported hy
the ledge, which m.kes the praéliee v"y eofy ; but
in cafe the muhiplicand (hO\J1d h3V~ more than nioe
plaees, tha< upper faee of the box may be .made broad–
ero Sorne make the rods with four different faces,
and figures on eaeh for dilferent purpoCes.
by the O1uhipl ication acd di\·jfi ...n of Jarge numbers are
much (;tc:litatod.
Al ,. ¡t e c."jlrufiion o/ NEPER'S ROO': fuppofe the
CCm Olon uble o( multipl:Cél1ion 10 be m~de upon a
plate of metal, ¡vory, or paíle. bo:ud. and then con·
ceive the fc\'eral columns (Handing dO'Nnwards (rom
,he digits On the head) ro be cut afunder; and thefe
are what \Ve call N~per's rods for multipll'cation . lJut
,hen .,here OluCI be a good number of eaeh ; for as
many tirnts as any figure is iD lhe muhiplicand, fa
rnany rods of that fpecies (i. e. with Ihat figure on the
top of'it) muCl \Ve have i Ihough ~x rod' of eaeh fpe–
cies win be fu/tieient for any cumple in eommon af–
fairs: there muCl alfo be as rods of o',.
Bu, before we explain ,he way of ufing ,hefe rods,
there is another thing to be knowo, fJiz . thar ,h e fi·
"gures 00 every rod are written in an arder difFerent
{rom thal in tbe 'oble. Thus, the liul. fquare fpace
or divifion in whieh the feveral produéls of ev<ry 1:0-
Iurno are wriucn, is divided iOlo tWO parts by a line
acrofs from the upper angle 00 the right 'o the lower'
on the Jeft ; and if the produél is a digit, i, is fe, in
,he lower divilion; if it has 'wo place., the firn is
fet ';n lhe low,r, and the fecoDd in the upper diviGon;
bu, ,he fpaces on the tOP are not divided; alfo there
is a rod of digits, not divided, whieh is called the in–
dex rod, and 01 this we need but ooe fingle rod. See
me figure of all ·the d iiFerent rods, and .he index , fe–
parate from one another, in Plate CXXXlV. fig . l .
Multiplicotion by NE'PER ' S RODS . Firn lay down the in–
dex rod; then on the right of it fet a rod whore top
is the figure in the highell place of the muhiplieand ;
next to this again. ret the rod ..whufe tOP is ¡he next
ligure of the muhiplieand; and fo 00 in order, 'o the
IirCl,ligure. Tbeo is your mul,iplieaod tabulated for
• I ,he oine digi.. ; for in the fame line of fquares
fianding againa ""y figure of the index rod, you
have lhe produél of tha, figure, aod therefore you
h..'e no more 'o do but 'o transf.. the produéls and
rum ,hem. Bu, in raking ou' theCe produéls from the
Tod., .he order in whieh the figures obliges you
to a very eafy and fmall addilion ; thu., begio tO take
out the figure in the Jower part, or unít', place, of
,he ~quare of ,he DrCl rod 0 0 the right; add ,he fi·
gure io the ~pper pan of this rod to th•• iD the lower
pan of the next, aod fo or., which may be done as
faCl .s you can lock on ,hem. To make .!Iis praélíee
as e1ear as poffihle, .ake .he following example.
Example: Tomul'iply 4768 hy 185. Havi~g fel
the rods ,ogether for the ntimher 4768 (ibid nO 2. )
againa 5 in the index, 1 find.1his oumber, byadding
aecording .to the rule, - - ' - 23840
Againfl 8, this Dumber 38144
Ag.inCl 3. this number 14 304
produa 1835680
To make .he ufe of the rods ye' more regular ..nd
eafy, they are kept in a /lat fquare box, whofe brtadth
is tha, of teo rod., aod the length tha' of ooe rod, as
,hiek as tO hold lix (or as many as you pleafe) the
Dioijion iy.N EPE R'S ROD' . Fi,lI ..hul..e your divifor;
Ihen you have i, multiplied by all the digits, out of
which you may chufe fuch convenien' divifo.. as will
be next lefs tO ,he figures in the dividend, and writ~
,he iodex anfweriog io ,he quotient, and fo contioually
,ill ,he work is done. Thus 2 t 79788, divided hy
612l, gi.esin ,he quotieot 356.
Having tahulated ,he divifar 6123, you fce .hat
6123 cannOt he had in 21 79; therefore take five pla–
ces, 00 the rods find a number that is equal or
neXtJefs,02 1797, which is 18369; that is, 3.imeo
,he divifor; wherefore fet 3 iD the quodent, and fub–
anél 18369 frorII the 6gures above, and .here will
remain 3428; 'o which add 8, the nex' figure ofVle
dividend, and fcek again 00 the rods for it, or the
De.x' lefs, whieh yoo wilJ find 10 be fíve .imes ; ,líere–
fore fet 5 io .he quo,ient, lod fubtraél 306 1S from
34:>88, and .here will remaio 3673; 'o which add 8',
.he figure in the dividend, and finding it tO be jua
6 ,ime. the divifor, fet fix in the quo,ieo"
6123)2t79788(356
18 36 9"
oeooo
NEPETA, in hotany, a genus of the didynamia gymno–
fpc:rmia cJars. The inte:rme:diate: lacinium of the inferior
Jip is crc:natc:d; the margin of the faux is re:iet'ted; and
the: {lamina are: Dear e:ach othc:r. Thc:rc: are: 14 fpc:cie:,.,
ocJy one of which, viz. the cataria, n~p, or cat·mint,
is a native of Brítain.
NEPH.';:W, a term relative tO uncle aod alln!, fignifying
a brother or Gller's fon; who, accordiog 'o the civil
law, is iD the .hird degree 01 confangui.y; but accordiog
'o .he canon, ID the fecood.
NEPHRITIC, fomethiog that relates '0 ,he ki.dney•.
NEPH RITt e \VO OD, a wood of a very denfe and compaa
tc:xture, and of afioe graio) brought us from Nc:wSpain,
in fmall hlocks, iD its natural Clate, and covered with
iu .
This wo~d i. a very good diuretic, and is faid 10 be
of