PERAMBULATO R. 
fitted to the fquared end of the arbor at K. L is a long 
fpring fcrewed on the block ; it prefles on the wheel A, 
to prevent it from lhaking by the motion of the carriage. 
A fmall triangular fpring is put under the middle of the 
dial-plate wheel for the fame purpofe. If the wheel of 
the carriage is exaftly five feet three inches in circumfe¬ 
rence, the brafs-toothed wheel which it turns Ihould have 
20 teeth, and that which ferves as a dial-plate (hould have 
80 ; it will then count five miles. If the carriage-wheel 
is either larger or fmaller., a mile fiiould be carefully mea- 
fured on a fmooth road, and the number of turns which 
the carriage-wheel makes in going this mile may eafily be 
counted by tying a piece of fine packthread to one of the 
fpokes, and letting the wheel, as it moves flowly forward, 
wind up the packthread on its nave. When the wheel 
has proceeded a half or a quarter of a mile, unwind the 
firing and count the number of turns which it has made. 
By the addition of another wheel of 81 teeth placed un¬ 
der the dial-plate wheel and moved by the fcrew C, with 
a proper hand fitted to it, and proper figures on the 
dial-plate, this machine would count four hundred 
miles.” 
In the Letters and Papers of the Bath Agricultural So¬ 
ciety, we find a defcription of an improved perambulator, 
called a pedometer, by Mr. Lewin Tugwell, of Bever- 
ftone. As the account contains fotne remarks upon the 
two inftruments we have already defcribed, we final 1 give 
it entire. 
“In the Cyclopaedia of Chambers, under the article 
Perambulator, it is faid, that the proper application of that 
machine is, for furveying of roads and large diftances, 
“ where great expedition, and not much accuracy, is re¬ 
quired.” This want of accuracy, as will be obvious 
enough to every infpeftor, arifes from the too-fmall di- 
menfions of its meafuring-wheel, which, in its applica¬ 
tion, too readily adapts itfelf to the cafual inequalities of 
the furface; and hence the defideratum of fome contri¬ 
vance for admitting a larger wheel, to obviate that de¬ 
left. This, fome years fince, was attempted by Mr. 
Edgeworth, whofe machine for the purpofe feems the 
molt fimple that can be conceived ; he, however, iimpli- 
city being in mechanics a criterion of excellence, (and 
probably from confidering, in addition to the above-men¬ 
tioned defeft in the old machine, its too great complex¬ 
ity,) feems to have gone into the oppofite extreme, and, 
almoft through the whole of his machine, to have facri- 
ficed utility to an unnecefl'ary degree of fimplicity. Mr. 
Edgeworth, in conformity to the above-mentioned fim¬ 
plicity of his odometer, found it neceffary to attempt no¬ 
thing more in its operations than the meafuring of roads, 
difiances, &c. and, even for this, unlefs where the ftones 
had previoufly been broken, and the roads worn fmooth, 
(inftances, for any confiderable length, rarely to be met 
with,) I found it, on trial, very inadequate. 
“In the fpecimen I have now fent, nothing has been 
omitted to render it capable of meafuring roads in gene¬ 
ral, with greater facility, accuracy, and expedition, than 
can be done by any other mode I have feen or heard of; 
while it alfo equally excels in furveying or meafuring of 
lands. By the common mode of meafuring thefe, by 
Gunter’s orany other chain, the progrefs (comparatively, 
in refpeft to that made by the pedometer) is ufually flow; 
and, while it ingroftes the conftant attention of two or 
more perfonsin company, the refult is fometimes erroneous. 
A perfon ufing the pedometer has not only, when at 
work, no need of an afliftant; but, while of himfelf he 
meafures with greater accuracy and expedition than is 
done by the chain, if an unemployed companion cafually 
attend him, he is at liberty, for the mo ft part, while the 
work goes forward, to take a (hare in converfation on 
any indifferent fubjeft. The idea of land-meafuring by 
this mode arofe from an impofition, which is, perhaps, 
but too frequently praftifed. A labourer’s talk-work 
being to be meafured, no one was at hand to carry the 
chain (the ufual term) but the labourer himfelf; when 
581 
the land was meafured, and the money paid, he went to 
the ale-houfe, got drunk, and boafted of having outwit¬ 
ted his mailer, in having Ihortened the chain, by gather, 
ing fome of the links in his hand at its fore end. 
“ This inftrument is reprefented at fig. 7. A, the 
Hock of the pedometer. BBB, twelve fpokes; one end 
of each inferted in the ftock ; the other fattened, with a 
fcrew, to the outward ring, or periphery, of the wheel. 
C, the periphery, being an iron ring, 165 feet, or one 
pole, in circumference, and divided into 25 equal parts, 
correfponding to the links of his chain for land-meafur¬ 
ing, Sec. DDD, twelve fmall plates, denoting the fepa- 
rate fpokes, each including two links of the chain above 
mentioned. The twelfth fpoke is divided at its foot 
for taking in the odd or 25th link. E, an iron axis, 
being afcrew with 320 circumvolutions, feparately marked 
on an engraved index on one of its (ides : in its applica¬ 
tion, it is fcrewed fall into the ftock of the wheel, and, 
when at work, revolves with it. F, a ftyle or alidade, 
being-an expanding fcrew-nut, embracing the axis, and 
fcrewing along it, as the latter revolves with the wheel; 
and, as each revolution of the wheel, when rolling on 
the furface, defcribes an exaft longitudinal pole, (and 
confequently four of them a chain,) the ftyle, being pen¬ 
dent, and moving to its proper figure, denotes the length 
of ground palled over, as divided into chains and poles 
on the index of the axis E, and into links on the peri¬ 
phery C. G, a fmall adjufting-fcrew, by turning of 
which the ftyle may be inftantaneoufly moved back to the 
beginning of the index, when, in land-meafuring, the 
given line has been afcertained in chains, poles, &c. H, 
a crofs or fquare, with fights for determining, in land- 
meafuring, the perpendiculars; fufpended at its ends on 
the axis, and occafionally to be detached therefrom, when 
ufed, with a.touch only of the finger and thumb. It 
furthermore afts (by the lower end of the ftyle F embra¬ 
cing alfo its ftandard) in preventing the faid ftyle from 
being carried round, by any polfible accident, with the 
axis as it revolves, which, before it was ufed, had fome¬ 
times taken place, and greatly embarraffed the account 5 
and, as the 320 divilions, marked poles on the index of 
the axis, are calculated for defcribing an exaft mile, the 
ftyle F, having palled over them, will then fcrew no far¬ 
ther; but, moving round with the axis, takes with it the 
the ftandard, and, ftriking it on the wrift of the operator, 
prevents the polfibility of his proceeding farther, till he 
has drawn his hand from between the faid ftandard-and 
the axis: having received the neceffary hint, he turns the 
fcrew G, puts back the ftyle F to the bottom of the index, 
and goes on as before. The ftandard of the crofs, being 
divided into five lengths, occafionally fubftitutes the ten- 
link rod, which is ufed for meafuring off-fets, See. and is 
alfo ufed for fmall diftances inacceffible to the wheel.” 
It has been fuppofed that the ancient Romans were ac¬ 
quainted with an inftrument of this kind. The founda¬ 
tion of this opinion is an exprellion of Julius Capitolinus 
in his life of the emperor Pertinax. The words are, 
“ Peralia (vehicvla), iter metienliu, et koras moujlrantia ; 
Carriages for meafuring the’length of the road, and mark¬ 
ing the time of the journey.” 
PERA'MES, a town of New Jerfey : eight miles north 
of Hackinfack. 
PERAMI', a town of the illand of Cuba: twenty-five 
miles fouth-eaft of Villa del Principe. 
PE'RAN in the SANDS, a village in Cornwall, on 
the Britifli Channel, north-eaft of St. Agnes. It has 
been almoft deftroyed by the fea-fands forced into it by 
the north-weft wind, fo that the inhabitants have been 
obliged to remove their church. 
PERANGLTST', adj. [from the Lat. per, and angujius, 
ftrait.J Very narrow. Cole. 
To PER'ARATE, v. a. [from the Lat. per, through, 
and aro, to plough.] To plough through. Cole. 
PERARO'LO, a town of Italy, in the Cadorin : two 
miles fouth of Cadora. 
PERAROO'R, 
