1809: ] 
ho filing’ or grinding, as they leave the 
plates or rollers perfectly smooth and 
regular. 
a 
NR, WILLIAM CONGREVE’S (LONDON) fur a 
néw Principle of measuring Time. 
_ This principle is founded on certain 
modes of detaching the time-measurcr 
from the first mover for an extent of du- 
ration, far beyond any thing yet effected, 
and which is not confined within the li- 
mits of ordinary detachments. Thus the 
only detachments hitherto effected have 
either been limited to a period somewhat 
Jess'than the smallest portion of time in- 
dicated by the vibrations of their time- 
measurer, and have therefore seldom been 
extended beyond seconds; or they have 
been effected by the intervention: of an 
auxiliary power between the first mover 
and the time-measurer, which indeed 
ought scarcely to be considered as falling 
within the class of detached movements,as 
the time-measurer, when discharged from 
the maintaining power is, in this case, 
still combined with another force. But 
by the system here specified, the duration 
ot the detachment of the time-measurer 
from the first mover may, without the in- 
tervention of any immediate power, be 
extended to a period comprehending any 
number of the smaller portions of time, 
indicated by the time-measurer; in other 
words the time-measurer shall indicate 
seconds, or any smaller division, and yet 
it shall be absolutely detached from the 
yaintaining power for a period of one or 
more minutes. The great’ difficulty of 
combining the actions of-the regulating 
principle of clocks with the maintaining 
power, so that the regulating organ should 
be operated upon freely and uniformly by 
the pure action of gravity, neither acce- 
Jerated nor retarded by the non-accor- 
dance of the first mover, has long since 
pointed out that the only true system of 
effecting this desideratum was by detach- 
ing them, as much as possible, rather 
than by combination. With the ordinary 
regulators, that is to say, with the com- 
mon pendulum or balance-wheel:the ex- 
tent of this principle of detachment, as 
already observed, is extremely limited ; 
for, as with the most perfect detached 
eScapement in use, the maintaining power 
is allowed to act on the pendulum for a 
certain portion of every oscillation, it fol- 
Jows, that with the common pendulum it 
would be’ extremely inconvenient to*de- 
tach the first power for an interval much 
fonger than a second ; in so high a law do 
the lengths of pendulums increage as to 
New’ Patents lately enrolled. 
573 
their times; so that to obtain a detach- 
ment of 2” would require a pendulum of 
13 feet 0,512 inches in length; to obtain 
one of a minute would require no lessa 
length than 11,738 feet 4.800 inches; 
the first, therefore, which would still be 
very limited as to any important correc- 
tion in its effect, would be of a most in- 
convenient, and the latter of an impossi- 
ble, length. By adopting the mode of this 
patent, however, it will be found tliat such 
or even a greater extension of detachment 
than a minute is practicable without any 
difficulty or inconvenience whatever, and 
even in a smaller space than is required 
frr the common seconds clock, The next 
general advantage is, that a clock made 
on this principle of extreme detachment 
requires a much less first power than @ 
common clock; for the power of the for- 
mer may be organized, so as to rest alto- 
gether for intervals of minutes, and to be 
limited when in action to less than half 
seconds between those intervals, while 
that of the latter is constantly exerted 
every second ; nevertheless, the maintain- 
ing power of the former need not have 
more to perform every minute than the 
other has every second. It follows, 
therefore, that a clock may be construct- 
edon this priciple to require only one 
sixtieth of the weight or power of a com- 
mon clock, or that with the same power 
it will go sixty times as long. Again, 
the mode of extreme detachment by di- 
minishing the quantity of the first force 
to so gréat a degree, and by the constant 
state of repose which it preserves in the 
train of the clock, removes almost entire- 
ly the strain and friction to which the 
works of a common clock are subject; 
so that the wear of the patent clock be- 
comes next to nothing, and it can, there- 
fore, scarcely ever reauire the application 
of oil, or get out of order. So also this 
system of detachment will be found great~ 
ly to simplify the train: in fact, the 
greater the extent of the detachment, the 
more simple will it be, by working from 
minutes instead of seconds, Notwith- 
standing which, however, the seconds, or 
any less division of time, may be indicat- 
ed with as much accuracy as in the more 
complicated train of the common time- 
piece. Mr. Congreve next describes his 
plan by means of drawings, observing 
that he has introduced a new modification 
of the action of gravity as applied to 
time-keeping, by taking as the time-mea- 
surer “a perfectly detached body, de- 
scending freely down an inclined plane :” . 
which modification, although it has never 
yet 
