a 
y shortly atter the first announc 
= 
or ve 
cal theory, devoted my attention to a realisat 
De oncmildiyerales which en theory rendered Jaina i 
“upon the regenerator as the appliance which, without being 
i papable Se cerducine heat when once really consumed, is ex- 
tremely useful for temporarily storing such heat as cannot be im- 
4 ately utilised in order to impart it to the fluid or other 
tance which is employed in-continuation of the operation of 
heating or of generating force. 
Without troubling you with an account of the gradual progress 
of these improvements, I will describe to you shortly the furnace 
which I now employ for melting steel. This consists of a furnace 
bed made of very refractory material, such as pure silica sand 
and silica or Dina’s brick, under which four regenerators or 
chambers filled with checkerwork of brick are arranged in such 
"a manner that a current of combustible gas passes upward 
- thrdugh one of these regenerators, while a current of air passes 
_ upwards through the adjoining regenerator, in order to meet in 
combustion at the entrance into the furnace chamber. The pro- 
ducts of combustion, instead of passing directly to the chimney 
as in an ordinary furnace, are directed downwards through the 
two other regenerators on their way towards the chimney, where 
_ they part with their heat to the checkerwork in such manner that 
_ the highest degree of heat is imparted to the upper layers, and 
_ that the gaseous products reach the chimney comparatively cool 
- (about 300° F.) After going on in this way for half-an-hour, 
‘the currents are reversed by means of suitable reversing valves, 
‘and the cold air and combustible gas now enter the furnace 
chamber, after having taken up heat from the regenerator in the 
reverse order in which it was deposited, reaching the furnace 
- therefore nearly at the temperature at which the gases of com- 
 pustion left the same. A great reversion of temperature within 
_ the chamber is the result, and the two first-mentioned regenera- 
"tors are heated to a higher degree than the latter. It is easy to 
conceive that in that way, heat may be accumulated within the 
BS chamber to an apparently unlimited extent, and with a minimum 
~ of chimney draught. 
Practically the limit is reached at the point where the materials 
composing the chamber begin to melt. Whereas a theoretical 
- limit also exists in the fact that combustion ceases at a point 
"which has been laid by St. Clair Deville at 5000° Fah., and 
__ which has been called by him the point of diSsociation. At this 
point hydrogen might be mixed with oxygen and yet the two 
"would not combine, showing that combustion really only takes 
place between the units of temperature of about 500° and 
4,500° Fah. 
ly To return to the regenerative gas-furnace. It is evident that 
' - there must be economy where, within ordinary limits, any de- 
gree of heat can be obtained, while the products of combustion 
| _ pass in the chimney only 300° hot. Practically a ton of steel is 
melted in this furnace with 12 cwt. of small coal consumed in 
the gas-producer, which latter may be placed at any reasonable 
ee distance from the furnace, and consists of a brick chamber con- 
taining several tons of fuel in a state of slow disintegration. In 
large works, a considerable number of these gas-producers are 
connected by tubes or flues with a number of furnaces. Col- 
lateral advantages in this system of heating, which is now 
a. extensively used in this and other countries, are that no smoke 
| _ is produced, and that the works are not enctimbered with solid 
a fuel and ashes. 
It is a favourite project of mine, which I have not had an 
opportunity yet of carrying practically into effect, to place these 
producers at the bottom of coal-pits. A gas shaft would 
have to be provided to conduct the gas to the surface, the 
lifting of coal would be saved, and the gas in its ascent would 
accumulate such an amount of forward pressure that it might be 
conducted to a distance of several miles to the works or places 
or consumption. ‘This plan, so far from being dangerous, would 
insure a perfect ventilation of the mine, and would enable us to 
utilise those waste deposits of small coal (amounting on the 
average to 20 per cent,) which are now left unutilised within 
the mine. 
y Another plan of the future which has occupied my attention 
is the supply of towns with heating gas for domestic and manu- 
facturing purposes. In the year 1863 a company was formed, 
with the concurrence of the corporation of Birmingham, to 
provide such a supply in that town at the rate of 6d. per 1,000 
cubic feet: but the Bill necessary for that purpose was thrown 
out in the Committee of the House of Lords because their Lord- 
ships thought that if this was as good a plan as it was repre- 
- ‘ 
sented to be, the existing gas companies would be sure to carry 
it into effect. I need hardly say that the existing companies 
have not carried it into effect, having been constituted for 
another object, and that the realisation of the plan itself has 
been indefinitely postponed. - 
Coal Question.—Having now passed in review the principal 
applications of fuel, with a view chiefly to draw the distinc- 
tion between our actual consumption and the consumption 
that would result if our most approved practice was made gene- 
ral ; and havihg, moreover, endeavoured to prove to you which 4 
are the ultimate limits of consumption which are absolutely fixed ‘ 
by theory, but which we shall never be able to realise completely, 
I will now apply my reasoning to the coal question of the day. 
In looking into the ‘Report of the Select Committee ap- 
pointed to Inquire into the Causes of the present Dearness of 
Coal,” we find that in 1872 no less than 123,000,000 tons of coal 
were got up from the mines of England and Wales, notwith- 
standing famine prices and the colliers’ strikes. In 1862 the =~ 
total getting of coal amounted to only $3,500,000, showing a er’ 
yearly average increase of consumption of 4,000,000 tons. If 
this progressive increase continues, our consumption will have 
reached, thirty years hence, the startling figure of 250,000,000 a 
tons per annum, which would probably result in an increase of 
price very much in excess of limits yet reached. In estimating 
last year’s increase of price, which has every appearance of being 
permanent, at 8s. per ton all round, and after deducting the 
13,000,000 tons which were exported abroad, we find that the 
British consumer had to pay 44,000,000/, more than the market 
value of former” years for his supply of coal—a sufficient sum, 
one would think, to make him look earnestly into the question 
of ‘waste of fuel,” which, as I shall presently be able to show, 
is very great indeed. The Select Committee just quoted sums 
up its report by the following expression :—‘*The general con- 
clusion to be drawn from the whole evidence is, that though the 
production of coal increased in 1872 ina smaller ratio than it 
- had increased in the years immediately preceding, yet if an ade- 
quate supply of labour can be obtained, the increase of produc-  — 
tion will shortly keep pace with that of the last few years.” A 
This is surely a very insufficient conclusion to be arrived at by 
a Select Parliamentary Committee after a long and expensive in- 
quiry, and the worst of it is, that it stands in direct contradiction 
with the corrected table given in the same report, which shows 
that the progressive increase of production has been fully main- 
tained during the last two years, having amounted to 5,826,000 
for 1871, and 5,717,000 for 1872 ; whereas the average increase 
during the Jast ten years has only been 4,000,000 tons. Itis to be 
hoped that Parliament will not rest satisfied with such a negative 
result, but will insist to know what can be done to re-establish : 
a proper balance between demand and supply of coal in prevent- Z 
ing its conversion into smoke or other equally hurtful or useless ‘ 
forms of energy. j 
In taking the 105 million tons of coal consumed in this country 
last year for our basis, I estimate that, if we could make up our 
minds to consume our coal in a careful and judicious manner, 
according to our present lights, we should be able to reduce that - 
consumption by 50 million tons. The realisation of such an 
economy would certainly involve very considerable expenditure 
of capital, and must be a work of time, but what I contend 
is that our progress in effecting economy ought to be accelerated 
in order to establish a balance between the present production 
and the ever-increasing demand fer the effects of heat. 
In looking through the statistical returns of the progressive 
increase of population, of steam power employed, and of produc- 
tion of iron and steel, &c., I find that our necessities increase at 
a rate of not less than 10 per cent. per annum, whereas our coal 
consumption increases only at the rate of 4 per cent, showing 
that the balance of 6 per cent. is met by what may be called our 
“intellectual progress.” Now considering the enormous margin 
for improvement before us, I contend that we should not rest 
satisfied with this rate of intellectual progress, which involves 
an annual deficit of 4,000,000 tons to be met by increased coal 
consumption, but that we should bring our intellectual progress ; 
up to the rate of our industrial progress, by which means we ~ 
should make the coal production nearly a constant quantity for 
several generations to come ; by which time our successors may 
be expected to have effected another great step in advance towards 
the theoretical limit of effect, which, as we have seen, lays so far 
above any actual result which we have as yetattained to, that an 
annual consumption of 10 million tons would give more than the 
equivalent of the heat energy which we actually consume, 
