563 
HORO 
locking, e is the locking-fpring, and f the pallet, as in 
fig- 97 - 
Inftead of palling our own judgment upon this fcape- 
ment, we lhall infert that of Mr. Ramfay, of Illington, 
who attended the committee in the Adelphi when it was 
examined. “ Having attended the committee upon Mr. 
Mendham’s fcapement, I think it a juftice due to the man 
of genius, to give my opinion farther upon it. As the 
principles of Mr. Mendham’s fcapement, and that of Mr. 
Mudge’s, which obtained a bounty from government, are 
much the lapse, I lhall compare the one with the other. 
The impulfe given to the balance without friftion, is exactly 
the fame as Mudge’s. The remontoir is bent up by the 
maintaining-power in a fimilar way to that of Mudge’s ; 
but, from the form of the pallet, which is a plain furface, 
it is not fo perfect. Mudge’s, from the form of the pallet, 
bends the remontoir always to the lame place, the other 
is bent higher or lower according to the force of the main¬ 
taining-power ; but, by forming the pallet like Mudge’s 
it would render them alike in that refpedt. The only 
other objection is the fpring-detent that detains the wheel 
when it drops from the pallet of the remontoir.; it is the 
fame as that of a detached fcapement, confequently ex- 
pofed to the whole force of the maintaining-power. To 
compenfate for thefe objections, the arc of vibration is 
not limited like Mudge’s, which is of great importance ; 
and, having only one remontoir, it is more Ample. It is, 
therefore, l'uperior to Mudge’s in having only one remon¬ 
toir; and,, being unlimited in the arc of vibration, it is 
fuperior to the detached fcapement in giving the impulfe 
without friftion.” 
Matthew's Improvement of Mudge .—In April '1808, Mr. 
Daniel Dering Matthew obtained a patent for improve¬ 
ments in the conltruCtion of watches and chronometers. 
Mr. Matthew’s fpecification contains the defcription of a 
fcapement intended to be a limplification of the one in¬ 
vented by Mudge; the axis of the balance is in the form 
of a crank, to admit its centre of motion to be in the 
lame line with that of the pallets, which are furnilhed 
with re-afting fprings; each pallet is raifed in fucceflion 
a certain diftance, by the teeth of the balance-wheel, 
where it is retained by a catch projecting from it, till the 
crank of the balance ftrikes it; this raifes the catch, and 
lets the tooth pafs that fuftained the pallet, which then is 
preifed towards the wheel by its fpring, a diftance equal 
to the height of the teeth, and re-acis on the balance 
during its fall ; this impulfe reftores to the balance its 
lofs of momentum, and it moves on in the fame direction 
till it ftrikes the oppofite pallet, furnilhed in all refpefts 
as the one delcribe'd, whole catch it then difengages, and 
is in return impelled by it in the contrary direction, in 
the fame manner as it was by the other pallet; end it 
thus vibrates alternately between the two pallets as long 
as the balance-wheel goes round. 
So far the conftruTion of Mr. Matthew’s fcapement 
follows that of Mr. Mudge; the only operation of the 
train is to raife or bend the pallet-fprings for" both ; each 
lias two pallets and two pallet-fprings, and the balance is 
kept in motion by their aftion alone ; and the catch of 
each pallet forms part of the pallet. The circumftances 
in which Mr. Matthew’s fcapement differs from Mr. 
Mudge’s, are, in the pallets moving in the plane of the ba¬ 
lance-wheel inftead of at right angles to it; in their much 
greater length; in their having fprings of but one curve, 
lhaped like the letter U, inftead of fpiral-fprings, and in 
thofe fprings afting on them either by joints, or fo as to 
caufe fome friCHon; and in the balance-wheel being form- 
ed of two wheels fattened together lb that the teeth of 
one fall exaftly between thofe of the other. 
In Mr. Mudge’s fcapement, the balance acis on an arm, 
projecting from the fame axle as the pallet, by a pin from 
the crank that ftrikes it at about the fame diftance from 
the centre as the catch on the pallet that Hops the ba¬ 
lance-wheel ; by which means the perculfion that detaches 
the catch is communicated to it in the fame degree of 
LOGY. 
force with which it is given on the arm. In Mr. Mat¬ 
thew’s fcapement, the crank itfelf ftrikes the arm of the 
pallet at about one-third of the diftance between the cen¬ 
tre of motion and the catch that connefls it with the ba¬ 
lance-wheel; the balance therefore requires more than 
three -times the force to detach the catch that is neceflary 
in Mudge’s plan, and is re-a Ted on by the arm of the 
pallet, in its return, for only one third of the diftance 
which the pallet is raifed by the teeth of the balance- 
wheel. The pallet in Mr. Mudge’s fcapement, from the 
manner in which it is conftruTed, re-afts on the balance 
for almoft the fourth of its revolution ; in Mr. Matthew’s, 
the pallet is an inclined plane, and is only raifed the 
height of the teeth, and could at moft re-act on the ba¬ 
lance the fame diltance; but, for the caufe above ftated, 
it only re-afls fora third of that diftance, or a fpace equal 
to a third of the length of the teeth of the balance-wheel. 
Each of the fprings of Mr. Matthew’s pallets is fup- 
ported near its extremity by a ftud, beyond which a re- 
gulating-fcrew, palling through it, makes it ftronger or 
weaker as it is more or lefs turned; the ftud is made of 
brafs, and the fcrew of fteel; therefore the greater expan- 
fion of the ftud will in fome meafure counteract the alter¬ 
ations of the fprings by heat and cold. A fmall catch 
moving on a fine fpring is placed fo as to fall on the arm 
or level of each pallet, near where the crank ftrikes it; 
this catch lets it go back only juft to the extent of the 
teeth of the balance-wheel, fo that the detent cannot be 
freed till it is removed; for this purpofe X fmall projec¬ 
tion rifes from the face of the catch, againft which the 
back of the crank preffes, in its way to the arm of the pal¬ 
let, and raifes up the catch, before it ftrikes the latter. 
Upon this fcapement the editor of the Athenaeum has 
the following remarks : “The form is certainly more fim- 
ple than Mudge’s, and would be more eafily executed 5 
but, as to preventing friCtion, we fee no imprpvement 
whatfoever; the great length of the arms of Mr. Mat¬ 
thew’s pallets are very objectionable, and would make 
the action between them and the balance very different 
from that in Mr. Mudge’s time-pieces; indeed a per- 
culfion operating beneath a long elaftic lever will tend in' 
fome degree to bend the lever inftead of railing it, which 
is an additional reafon againft its ufe here. We objefl 
to the joints propofed between the fprings and the levers 
of the pallets, both on account of their complication and 
the lhake to which they mult be liable on every change 
of motion. The fmall locking-catches prevent the detent 
being difengaged by any violent external force before the 
crank comes forward to releafe it; but we fhould imagine 
that the force of the pallet-fprings would be fufficient to- 
prevent any power from difengaging the detent that was- 
not great enough to deftroy the work. While we objeCt 
to fome of Mr. Matthew’s alterations of Mr. Mudge’s 
fcapement, we think at the fame time he could eafily al¬ 
ter his plan fo as to obviate them. The pallets moving 
in the lame plane as the balance-wheel is certainly an im¬ 
provement; the defefts of the joints which unite the 
fprings to the pallets could be eafily remedied, by adopt¬ 
ing another form of fpring. The moft ferious objection 
to Mr. Mudge’s time-pieces ariles from their complica¬ 
tion; we therefore advile Mr. Matthew to Itill farther 
Amplify his; and to try the effeCt of a Angle pallet and ; 
fpring, with the fmall alterations which will be neceflary 
to perfeCt the work in this form. 
“Mr. Mudge’s invention of working the balance by an 
intermediate lpring between it and the train, which frees- 
it from every irregularity of the train, lias been improperly 
called a remontoir, which confounds it with the invention- 
known by that name, applied between the main-fpring 
and the train, and merely intended to equalize the irre¬ 
gular force of the main-fpring. It has alfo been impro¬ 
perly called a detached fcapement, which confounds it with- 
the free fcapement, fuppoled to be firft contrived by Le 
Roy, in which the balance is left entirely to the vibra* 
tions caufed by its own fpring, except during the fliort 
interval 
