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friction. 
TRANSACTIONS OF THE SECTIONS. 99 
graduated scale, any increment of heat obtained by the combustion of the gas. This 
increase of temperature, he stated, was found in practice to attend the admission of 
the jets of air, and to decrease by shutting off all access of air to the diffusion appa- 
ratus: there is, therefore, in this arrangement one supply of air for the gas by the 
perforated air distributions, and another for the fuel on the grate by the ordinary 
mode of an open ash-pit. Mr. Dircks explained a drawing of an ingenious pyrome- 
ter 104 feet long, extending through the entire length of a chimney at the works of 
Messrs. Ellis and Noton, Engineers, Manchester, who had become so familiar with 
this instrument, being self-registering, that they could distinguish all the alternations 
of work and stoppages occurring at the furnace. 
Mr. Dircks added some statements as to the advantage and practicability of in- 
creasing the evaporative power of the boiler itself, and a table founded on experi- 
ments of the relative calorific and commercial value of different sorts of coal and 
turf variously prepared for the furnace. 

| Description of a Furnace for Economizing Fuel and Preventing Smoke. 
By Joun CHANTER. 
The author exhibited drawings of the arrangements he employed for these pure 
poses. It differs from Mr. Williams’s in the two essential particulars of heating the 
air before it is admitted to the fire, and of giving a reciprocating motion to the fire- 
bars, for the purpose of freeing them from clinkers and ashes. The air is admitted 
into an air-chamber to be heated, and a “ deflective arch,” at the bottom of the 
boiler, turns the generated gases on to the hot fuel, supplied with its requisite por- 
tion of oxygen through the clear fire-bars- 

Mr, J. Juckes exhibited the model of his Furnace for Burning Smoke, with fire- 
bars consisting of endless chains passing over rollers, which was explained at the last 
Manchester meeting. 

On the Application of Water as a Moving Power. By Mr. Ryan. 
In principle, the machine described resembled Barker’s mill. 
On a New Oil for Lubricating Machinery. By J. 1. Hawk1ns. 
Mr. Hawkins described a practice which has lately been adopted in some parts 
of the United States, of procuring oil and spermaceti from pigs. The pigs are driven 
into the woods to feed, and after some months they are brought back and fattened 
with Indian corn. The animals are then killed and boiled altogether, for the pur- 
pose of extracting all the lard, which is then converted into stearine and elain. ‘The 
oil thus procured is of a remarkably fine quality, and well adapted for lubricating 
machinery. 


Mr. Hawkins read a paper on the friction of water against water, as exemplified 
in the well-known experiment of emptying a vessel full of water by sending a jet of 
the fluid through it. This friction of the particles of fluid against each other caused 
the principal obstruction toe the motion of ships through the water; and he con- 
ceived that it would be advantageous to grease the bottoms of ships to diminish the 

On the Formation of Concrete. By J.1. HAWKINS. 
In this communication the author showed the importance of having the stones of 
the proper sizes, so that the smaller ones should as nearly as possible fill up the in- 
terstices of the larger, Where the sizes were properly adjusted, he found that one 
proportion of lime to twenty of shingle formed a stronger concrete than when larger 
proportions of lime were used. Some engineers are in the habit of using one of lime 
to six of shingle, and the proportions generally used are as one to eight, A spe- 
cimen of concrete made in the proportions he recommended, and with shingle of 
proper sizes, was found after a short time to be stronger than an old Roman wall. 
HZ 
