52 G. W. Hough on an Automatic printing Barometer. 
equal to that of the wheel into which it gears. This arrange- — ; 
ment prevents any motion, except it be communicated by the 
units wheel. The whole mechanism is therefore locked together, 
and it is just as impossible for it to get out of order as it is for 
ordinary clock gearing. 
The chief merit of this combination is, that it will carry for 
_ten either forward or backward. This principle is necessary 
in any meteorological printing instrument. We need no extra 
apparatus for bringing the type in line, since if the mechanism 
is well constructed, it will always arrange itself. When once 
set it will remain so, for no change can be made without ungear- 
ing the machine. 
e use ordinary type which are set in separate disks, being 
afterwards screwed fast to u, ¢, and h. In case a type is acci- 
dently damaged, or broken, another can be inserted in a few 
minutes. Steel type would undoubtedly be the best, as being 
more durable and less liable to damage. We should add, that 
the wheels ¢ and 4 have each 50 teeth; five teeth being moved 
at one impulse. 
The printed results are received on the strip of paper 7, moved 
by the clock-work &, fig. 83, which at the same time regulates 
sure. This same clock raises a small hammer A, by means of a 
and cylinder is an gered half-second’s 
nd. It 
time; for the paper slip co the time already printed on the side, 
sary to add the date and integer inches. 
The following is a fac simile copy of the record as printed by _ 
the machine. The numbers on the left hand are the hours from __ 
noon of the 11th to the noon of the 12th. The remaining fig- _ 
i of 
ures are the barometrical heights expressed in thousandths 0 
inches. : 
24 Oe one Do oi gewnd eae aes ett) cence h ee ons ie 
ey Se ag NOM a a Ce ae ee 
