293
METEOROLOGICAL INSTRUMENTS—BAROMETERS AND THERMOMETERS. [Class X.
from 1G by 8 inches to 24 by 12 inches, and is com-paratively inexpensive.
For use, it is charged with a composition of powderedcharcoal, nitrate of potass, and gypsum, in the followingproportions: powdered charcoal, 20; nitrate of potass,GO ; aud gypsum, 5. These materials are boiled togetherin water, and afterwards dried in a stove, at the tem-perature of 100 3 . The whole is moulded into the formof a brick, down the axis of which penetrates a hollowcavity, for the reception of a bottle, which contains amixture of chlorate of potassa and sugar, surmounted bya globule of sulphuric acid. The charge so preparedis placed in a cylindrical vessel, perforated in manyplaces, which is itself within another cylindrical vessel,also perforated for the passage of the gases; both theseare contained within a double cylindrical receiver, thelower part of which contains a quantity of water. Theapparatus is closed by two covers; in the outer of whichis an opening for the escape of the vapour. In the centreof the cover is placed a spike, for the purpose of breakingthe glass bottle deposited iu the cavity of the charge.The spike being forced down breaks this bottle, and thesulphuric acid, falling on the mixture of chlorate ofpotassa and sugar, causes instantaneous combustion, andspreading over the charge, causes a second ignition atonce to take place. The gases thus formed pass throughthe perforations, and by heating the air in the waterchamber, and causing it to expand, forces the water upa tubular passage into the spaces between and around thecylindrical vessels placed each within each; and beingthus converted into vapour, mixes with the gases, andescapes by the discharge tube. The discharge forms adense cloud, which continues until the charge is con-sumed and the water quite exhausted.
On Thursday, September 26, several gentlemen of theJury assembled at Battersea Fields to witness Mr. Phillips’fire annihilator in operation. There -were present—SirJohn Herschel , Mr. Glaislier, Mr. Bowerbank, and Pro-fessor Collodon. A rough wooden house, two storieshigh, filled with planks of wood, shavings, &c., was seton fire, and the doors and windows fast closed, previouslyto which, a quantity of spirits of turpentine had beenpoured over the combustibles in the interior, from whichin the course of a few minutes the flames were seenissuing from the windows, and on the door being burstopen presented an unbroken sheet of flame. The fireannihilator was then brought forward, and the vapourdirected into the doorway. The effect was almost instan-taneous. The great mass of flame was at once extin-guished, and at the same moment dense volumes ofsmoke were seen issuing from the same place. In thecourse of a few minutes the fire was entirely extin-guished, leaving the walls of the house standing, thoughconsiderably charred. Ten minutes after (a few lingeringtraces of fire to the windward being extinguished withwet mops), the Jury entered without inconvenience; theair within being cool and moist. The experiment,which must be considered as a severe test to the powersof the machine, was considered satisfactory in theextreme. Shortly after, a tank, containing a mixture oftar, shavings, and other combustible matters, was ignited,and afterwards extinguished by one of these machineswith equal success; the machine being placed to wind-ward, and the gas thus swept over the burning surface,in a state of most violent combustion, instantly anni-hilating the flame.
The idea which Mr. Phillips has successfully appliedto his fire annihilator was suggested to him by witness-ing, some years ago, in the Mediterranean Sea , an erup-tion from an island, thrown up from a depth of 80fathoms ; he observed that, where the vapour formed bythe boiling water, and precipitated upon the lava, camein contact with the flame, the latter was instantaneouslyextinguished.
The fire annihilator, in its action, may be said to re-semble that of a pump drawing water, or the condenserof a steam-engine. The vapour which issues from itenters the building in a highly-expansive state, andextinguishes the flame chiefly by the presence of gasesadverse to combustion, but partly also, no doubt, by
reducing it to a temperature lower than that at whichflame can exist. By degrees, the room being full ofvapour, the temperature decreases, and the vapour con-densing into water, fresh air enters to supply its place,and renders it. possible for men to enter, and completethe work of extinction of the embers. The machine isunattended with any practical difficulties in its use; themixture of steam and gases may be produced within afew seconds after striking the top for the purpose ofbreaking the little bottle. The vapour itself possessesthe advantage of being less destructive to the uncon-sumed articles with which it comes in contact, and beingalso a more penetrative medium than water, is bettercalculated to act simultaneously upon the innumerableparticles of gas which combine to produce flame. It isstated to be perfectly innoxious to human life, which, ofcourse, must be understood to mean during that shorttime, and in that state of admixture with air in whichmen have occasion to inhale it.
When we take into consideration the large number offires which, both by day and night, endanger the life anddestroy the property of individuals situated in or nearthe metropolis, the production of a machine such as thatwhich Mr. Phillips has exhibited, promises to be of veryconsiderable utility. By being provided with one ofthese, each householder is possessed of an instantaneousmeans of checking a fire at its commencement, longbefore any great destruction of life or property could beapprehended. Its advantages on ship-board can scarcelybe over-estimated, and are most obvious. The Jury,considering it well adapted in its application to the pur-pose intended, and being perfectly satisfied with itsperformance in this instance, have awarded Mr. Phillipsa Prize Medal.
Wf.are (Xo. 386, p. 451) has exhibited a fire anni-hilator, designed, by means of a discharge of gas, toextinguish fire, and prevent the ignition and self-com-bustion of inflammable matter. As the Jury have hadno opportunity of examining the machine, or becomingacquainted with its construction, they are not qualifiedto decide upon its merits.
Meteorological Instruments.
Considering the greatly increased attention which hasbeen paid within the last fe\v years to meteorologicalresearches upon a systematic plan, a part of which is theusing instruments well adapted to the work, it is bothsurprising and very lamentable to perceive, among thenumerous exhibitors of barometers and thermometers,instruments of so ordinary and inefficient a construction,the greater part of them being ill adapted and totallyunfit for meteorological observations. In the barometersexhibited, the majority of the makers, in their anxiety torender them elegant and decorative articles of furniture,have paid but little attention to its essentials as a philo-sophical instrument. Their forms, as exhibited, arevarious, it is true, not as might be expected with a viewto discover that construction likely to give the soundestresults, but more, it would appear, to suit the require-ments of those who can see in a barometer nothing moreuseful or important than a piece of household furniture,destined to take its place among the usual appurtenancesof a well-furnished hall. This is much to be regretted,the barometer ottering—as it does—so wide a field forthe exertions of the instrument-maker to fit it for theincreasing requirements of the present advancing state ofmeteorological observation. Iiow disappointing it is tofind all their exertions directed to the enshrouding it ina case w'hich, with few exceptions, renders it not onlycumbersome and inelegant, but, as typifying the apathyof a large class of instrument-makers to the fundamentalprinciples of its construction, to us most offensive: on thescore of inelegance of construction, we may, however,except those exhibited by Elliott and Sons, (No. 320),which are fairly models of chaste design and excellentwood-carving. It would be well for the purchasers ofthese decorative and ill-constructed barometers to re-member that bv their adoption and use of such instru-ments they forfeit all claim to scientific notice, and theyshould also remember that to the well informed no in-