1828] 
fully merits. It would be desirable to know 
whether some very singular carelessness has 
not been displayed for some time as to the 
state of the gas. Certainly no one could 
have sat in the dress circle for the last year, 
er gone down the stair-case leading to the 
piazza, without ascertaining for himself, 
that the material of some most pernicious - 
effluvia was at work below. Whether 
Managers ever made the discovery for 
themselves, every passer-by might ‘nose 
it in the lobby ;’’ and there the nuisance 
remained, poisoning the air, and the audi- 
ence along with it, month after month. 
The employment of gas in houses, where it 
must often be enclosed in unventilated 
apartments, has been so often shewn to be 
hazardous by its explosion, that it must be 
difficult to justify its employment in a build- 
ing, where not merely a few tables and 
chairs, but the lives of some thousands, 
must be risked ; and we shall rejoice if this 
accident, perilous and painful as it is, should 
be the means of expelling gas from the in- 
terior of every public building, where it can 
escape unfelt, and be undiscovered, till some 
thoughtless hand. touches it into explosion. 
Its uses are fairly defined; it is an admira- 
ble street-illumination; it may light our 
Monthly Theatrical Report. 
651, 
signal posts, and beacons; in open shops, 
and other places, exposed to a constant con» 
munication with the external air, nothing 
can be safer or more serviceable. But, in 
our churches, our ware-houses, our dwel- 
ling-houses, and, above all, in our theatres, 
the chances of explosion are so many, the 
difficulty of providing against it so great, 
and the loss of life so menacing and sweep- 
ing, that its use becomes scarcely less than 
a public crime. 
The managers and proprietors of the 
theatre, have distinguished themselves, in 
the present calamity, by yery meritorious 
exertions; and we are much gratified by 
saying, that their efforts to alleviate the 
distress of the hurt survivors, and their fami- 
lies, have been considerably successful. The 
transfer of a portion of the company to the 
Lyceum, has been well received. Kean’s 
performance has revived in its popularity, 
by the greater facility which the size of the 
theatre offers; and the usual favourities of 
the audience have played with an increased 
effect, which we hope will some time or 
other teach managers the advantage of 
limiting their theatres to a size, in which an 
audience can hear without a trumpet, and 
see without a telescope. 
VARIETIES, SCIENTIFIC AND MISCELLANEOUS. 
es 
Ulrie’s Chronometer.—A most import- 
ant improvement, or rather combination of 
improvements, has lately been effected in 
time-keepers, by a German of the name of 
Ulric, who has succeeded in reducing to 
practice several theoretical improvements, 
which had hitherto defied the skill of our 
_ most experienced artists. In the patent 
marine time-keeper we are now describing, 
_ the irregularity, arising from inequality in 
the power exerted by the main spring, is 
prevented by the transfer of the motive 
power to a spring lever; which, capable of 
_ receiving only a certain portion of power 
~e _from the spring, can only impinge on the 
‘balance axis with a certain and determinate 
force. This force, invariably the same, 
will, of course, always impel with the same 
effect. Tio secure an isochronous motion, 
the spiral, or pendulum spring, is made per- 
 fectly taper, an object obtained only through 
the medium of an elaborate tool, con- 
_ structed for the express purpose of reducing 
them to this form. The variation between 
the sea and land rates, in the best chrono- 
meters hitherto constructed, is remedied, 
by the introduction of a balance, without 
iron or steel, consequently free from mag- 
Aiartic properties, or influence, yet possessing 
@ compensating power, considerably more 
sensitive, and more active, than any pre- 
viously used, without any liability to per- 
vent distortion of its true figure, by any 
msition from one temperature to another. 
Ky / 
4 
The imperfection, technically called trip- 
ping, and which is so frequently the cause of 
much error and miscalculation, is entirely 
prevented ; nothing short of a violence suf- 
ficient to destroy the machinery of the time- 
piece can cause it to trip. They admit of 
being cleaned without the danger of dis- 
turbing their rates, and, indeed, without 
disturbing those parts on which ‘the accu- 
racy of their movement depends; a quality 
which every one, who has the use or care 
of chronometers, will be able to appreciate. 
The most inexperienced person may be 
safely intrusted to wind them up, no change 
of position being necessary, and no possibi- 
lity of over winding or winding wrong, ex- 
isting. An increased solidity is introduced 
into every part, diminishing almost te anni- 
hilation the risk of accident by any ordi- 
nary occurrence, and, consequently, re- 
moving one very fruitful source of anxiety 
to the navigator. We are happy to bear 
personal testimony to the unreserved and 
courteous manner in which Mr, Croucher, 
who has obtained the patent from Ulric, 
submits these valuable instruments to the 
inspection of all who feel interested in the 
subject. 
To harden Plaster Casts and Alabaster. 
—The following process has obtained a 
patent in France. The piece of plaster, or 
alabaster, after being shaped, is put for 
twenty-four, hours into a furnace. If the 
piece is ,only cighteen lines thick, thre¢ 
402 
