358 
and shewed his interest in the promotion of the use of peat 
charcoal, by forwarding specimens to the Exhibition of 1851. 
This reply, contains a good deal of truth ; when an article 
of any kind has been puffed and praised too highly, and we 
find on using it that its value does not reach the erroneous es- 
timate formed of it, we are often led to underrate and lose sight 
of the real intrinsic value which it does unquestionably possess. 
The question however, is, whether peat charcoal really 
does possess the valuable properties assigned to it ? Totally 
unconnected with any company or scheme for its manufacture, 
my own experience has led me to answer in the affirmative. 
We all know, that although laboratory and lecture experi- 
ments may be successful, yet utter failure may attend the 
application of a great and good principle in the large and 
commercial scale. To ensure success, a process must not 
only be good, but capable of practical and economical appli- 
cation on the large scale. 
Lady Frankland Russell, of Thirkleby Park, Thirsk, has 
demonstrated the practical as well as economical application 
of peat charcoal to filtering the sewage of a town, by the 
construction of a sewage tank at Aylesbury, in Buckingham- 
shire, which has been in successful operation during the last 
two years to the great benefit of the locality. 
I have been favoured by Mr. Yarrow, of London, Civil 
Engineer, with a copy of his Report to Lady Frankland 
Russell, on the working of this Sewage Filter; it is as 
follows : — 
Mr. Yarrow's Report on the Aylesbury Sewage Filter. 
88, St. James's Street, May 13th, 1855. 
Lady Frankland Russell, 
Dear Madam, 
In accordance with your instructions, I have prepared 
the accompanying model of the Aylesbury Filter, constructed 
by your Ladyship's order in 1852, for purifying the town 
sewage by means of peat charcoal 
