1874.] Engineering. 267 
the danger produced by constructing a boiler so that the failure of any one 
stay would be fatal to the whole structure; and this is the more important 
since stays are seldom made to take the strain equally. The importance of 
the proceedings of this Experimental Commission was considered so great 
that the subject was brought before Congress, by whom 100,000 dollars have 
been voted to carry out similar experiments on a larger scale, and the Com- 
mission appointed for that purpose has made a beginning, but has not yet 
issued its report. : 
According to the report of the Midland Steam-Boiler Inspe&ion and 
Insurance Company for the last half of 1873, they had 3555 boilers under 
their care, and during that period there had been no explosion of any boiler 
under their inspection. In consequence of the explosion of a blast-furnace 
boiler, attention has been directed to the safer working of such boilers of 
considerable length, it is suggested that they should be divided into separate 
lengths connected with narrow necks or pipe connections so arranged as to 
prevent rigidity. The feed water, in such case, would enter the back com- 
partment and overflow into the next one, and then again into the front com- 
partment, supposing the boiler to be in three compartments. The last 
compartment alone would require a water-gauge. The water, therefore, 
would gradually advance from back to front, while the heat would be greatest 
in the front. In this arrangement, apart from the diminished danger of 
explosion, it will be seen that the mud would be deposited in the back end, 
where, the heat not being sufficient to form it into a hard scale, it could be 
discharged by the blow-cock. 
With regard to tube boilers, it is remarked that they can evidently be 
worked with success where the high pressure for which they were designed 
is required, and where good water can be obtained, but they do not offer much 
advantage for low pressure, or with the average scale making water. The 
experience of the past year confirms the opinion that no boiler is free from 
the danger of explosion if not well looked after; and that the best means of 
preventing explosion is to insist upon frequent inspection and careful attendants. 
London Water Supply.—The Kent Company are now giving a constant 
supply to about 2200 houses in Deptford, and is extending the constant 
service to other parts of its distri. ‘The New River Company have now the 
power of affording effective constant service in their district; and they have 
also commenced a new high service covered reservoir, to contain one million 
gallons, at Southgate, in anticipation of the requirements of the water supply 
to Edmonton parish. This Company has, in a number of cases, afforded 
constant supply by means of stand pipes, and have agreed with a Committee 
of the Corporation of the City of London to furnish constant supply at once 
to a large number of the houses of the poor within the City bounds, wherever 
the arrangements of the officers of the Corporation in connection therewith 
are completed. The East London Company are extending the constant 
system of supply in their distri@, and have completed the arrangements for 
supplying the houses in one of their distri¢ts. The Southwark and Vauxhall 
Company are constructing covered service reservoirs at Nunhead, to contain 
18,000,000 gallons, and are erecting additional engine power for high-pressure 
constant supply. Additional boilers and works are also being constructed at 
Hampton. The West Middlesex Company are giving constant supply to a 
number of houses on the application of the owners, who have provided 
fittings according to the Board of Trade Regulations. This Company is also 
constructing extensive works and additional engine-power at Hammersmith 
and at Hampton to ensure effective constant supply. The Grand Junction 
Company have completed a high service reservoir near Kilburn, to contain 
6,000,000 gallons for constant supply, and have laid a line of main pipes to 
connec up this reservoir with the works at Campden Hill, and are likewise 
erecting additional boilers and works at Hampton. The Lambeth Company 
are also carrying out extensions and improvements to their Works. At 
Moulsey the construétion of reservoirs is being proceeded with, to contain 
