In the article on "Gas, Air, and Water Power" in the _Journal_ for Dec.
8 last, you state that you await with some curiosity my reply to certain
points in reference to the compressed air power schemes alluded to in
that article. I now, therefore, take the liberty of submitting to you
the arguments on my side of the question (which are substantially the
same as those I am submitting to Mr. Hewson, the Borough Engineer of
Leeds). The details and estimates for the Leeds scheme are not yet in a
forward enough state to enable me to give them at present; but the whole
case is sufficiently worked out for Birmingham to enable a fair
deduction to be made therefrom as regards the utility of the system in
other towns. In Birmingham, progress has been delayed owing to
difficulties in procuring a site for the works, and other matters of
detail. We have, however, recently succeeded in obtaining a suitable
place, and making arrangements for railway siding, water supply, etc.;
and we hope to be in a position to start early in the present year.

I inclose (1) a tabulated summary of the estimates for Birmingham
divided into stages of 3,000 gross indicated horse power at a time; (2)
a statement showing the cost to consumers in terms of indicated horse
power and in different modes, more or less economical, of applying the
air power in the consumers' engines; (3) a tracing showing the method of
laying the mains; (4) a tracing showing the method of collecting the
meter records at the central station, by means of electric apparatus,
and ascertaining the exact amount of leakage. A short description of the
two latter would be as well.

TABLE I.--_Showing the Progressive Development of the Compressed Air
System in stages of 3000 Indicated Horse Power (gross) at a Time, and