114 REPORT—1849. 
will be judiciously brought into practice as experience will dictate, until the Davy 
lamp shall be no longer necessary for the common collier, the danger of explosion 
almost or altogether obviated, and the heaith of the miner greatly promoted? 
On the Use of Rockets in effecting a Communication with Stranded Vessels. 
By A. G. Carte. 

On a Desiccating Process. By Rosert Davison, CB. 
All previous modes of drying which have been employed consist in generating 
heat by simple radiation, or throwing off heat from a heated surface, whether the 
surface be brick flues, cockles, steam or hot-water pipes. Heat is easily attainable 
in this way, and almost to any grade of temperature, but heat is not the only essen- 
tial for drying. leat facilitates the evaporation of the watery particles, but a cur- 
rent is necessary ; otherwise all the water which is thus converted into vapour will 
only tend to charge the chamber with steam, and it is not until the steam has ar- 
rived at a certain excess or pressure that it will make its escape and the operation 
of drying really commence. The amount of current obtainable in this way is pro- 
portioned to the rarefaction and quantity of air admitted and allowed to come in 
contact with the heated medium. 
The paper then proceeds to show that it is not only a moving, but a rapid current 
which is the great desideratum for all drying purposes, and that it is the impulsion 
of atmospheric air at the velocity of the hurricane, or 120 feet per second, or any 
increased speed, combined with elementary heat under perfect control, which con- 
stitutes the desiccating process. " 
The means by which the two operations of current and heat are created and kept 
up are as follows :—The apparatus consists of a series of cast-iron pipes of. a semi- 
circular form, so united together with straight pipes at their base as to form one 
continuous pipe; these being set in brickwork, with a common furnace in the centre, 
comprehend the heating medium. The current is created by a common blowing- 
fan, which can of course be driven at any required speed. It therefore only remains 
to be observed on this head, that the chief difficulty has been to discover what 
amount of surface or metal was necessary to secure or maintain a certain tempera- 
ture in a given space: this has been found to be 28 feet superficial, or about 10 cwt. 
of metal for every 1000 feet of space of chamber. 
In speaking of the application of the process to purifying brewers’ casks, the au- 
thor mentions, as a proof of the success of this portion of the invention, that 
upwards of one million casks have been thus cleansed and purified, and that the cost 
does not exceed 14d. each cask ; whereas any other method where unheading is re- 
sorted to, the cost is 6d. at least, Messrs. Guinness of Dublin are mentioned as 
having adopted the process. 
The paper proceeds to describe the theory upon which dry heat is more important 
than moist or steam heat for this purpose, and also why water in the pores of the 
wood, and acid from the beer, are direct antagonists, quoting on this subject the 
experiments of Mons. Dutrochet, who discovered that one drop of acid in one ounce 
of water became mouldy in eight days. 
In speaking of the application of the process to the seasoning of wood, the author 
alludes to the numberless treatises and cures for what is termed dry rot, but which 
a writer says is a misnomer, “ the rotting principle being moisture,’’ and asserts his 
belief that all immersions in water or exposing the wood to steam is calculated not 
only to dissolve and wash away the gums which nature has provided to bind the 
fibres together, but that all such methods have a tendency to sodden and decompose 
the woody fibre itself; while, on the other hand, the desiccating process is attended — 
with an opposite result. The improvements are thus described :— 
1, The process is a true imitator of nature, or those elements which are acknow- 
ledged to be the best seasoners of wood, viz. the March wind and summer heat, with 
the advantage of both being continuous and controllable until every grain or atom 
of moisture is expelled. 
2. The greener the wood the easier and more perfect the expulsion of the watery — 
particles. 

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