67 
As a practical conclusion that may prove useful to the 
manufacturing interest in the Stroud valley, the ordinary power 
of the river Frome, computed from the average of the summer 
and winter flow per foot of fall at the wheel, is indicated in the 
following table :— 
River Frome 
. River’ Frome 
at scr gaa at Ebley 
River Frome 
at Chalford Les’ 
Mill 
River Frome 
at Stanley and 
Downton Mills 
River Frome 
at Ryeford 
Theoretic | Effective | Theoretic | Effective | Theoretic | Effective | Theoretic | Effective Theoretic | Effective 
H.P. HP. H.P. H.P.; HP. H.P.. H.P. EP, H.P. H.P. 
4°84 
20°82 | 12°49 
13°15 
7°67 4°60 
8-07 
7°89 
I have referred to the river Chelt, which I have had occasion 
to gauge periodically a great number of times, for the purpose 
of giving you the character of a stream traversing a clay dis- 
trict (the Upper Lias.) The gaugings show a variation between 
minimum and maximum flow of 1 to 39. They were taken at 
the site of the former Dowdeswell mill, the drainage area above 
being 3 sq. miles nearly. 
The applicability of Jounn’s law, as bearing on the “tempe- 
rature of springs and Hydrogeological enquiry generally,” is a 
subject of much interest. The fact that friction produces 
heat has been known from the earliest times, but it rested with 
Jouts to prove, in 1843, by an agitator working in water and 
actuated by a falling weight, that to produce a unit of heat, 
that is, the amount required to raise the temperature of a 
pound of water (at 32°) one degree Fahrenheit, was 772 pounds 
falling one foot. ‘No language,” says Professor OsBorNE 
Rrynotps, “can be too strong in which to express the impor- 
tance of this discovery ;” admitted at once as a proof that the 
transformation of heat into mechanical energy, or of mechanical 
energy into heat always takes place in a definite numerical 
ratio. 
Let me shortly ask your attention to two experiments lately 
made by me. 
First experiment Feb. 16th, 1886, at Cirencester: Took 
temperature of spring water issuing from the bore pipe (about 
50 gallons per minute) at the bottom of the Water Works 
F2 
