208 DE llAXCE : UNDERGROUND WATER-SUPPLY AND RIVER FLOODS. 
paiuted on them in white and black, giving the height in feet above 
the Ordnance datum, of the mean sea level, to facilitate comparison, 
and the height of the water upon them was daily noted by the county 
Constabulary on their ordinary rounds. On important points self- 
recording apparatus to ascertain the daily quantity of water carried 
down might be ]^laced, under the direct supervision of the Board's 
official, who should organize a system of flood warnings by telegraph. 
In the meanwhile much valuable information may be rescued 
from oblivion by observers, who will note the height marked by floods 
at important points, and the height in reference to the Ordnance 
datum given, date and local circumstances recorded. If such a work 
were undertaken by the leading provincial societies a valuable map 
of facts would soon accrue. I venture to think it is also the duty of 
scientific societies to urge upon the government the necessity of 
Parliamentary power being given to the county councils ; to sanction 
the small charge that would have to be made on the water ; to fix 
g-uages on the county bridges ; to inaugurate a system of flood- 
signalling, and to make such contributions, regulated by the area 
included, as would give funds for the inspection of rain-guages, and 
the tabulation of the averages of the rainfall of the district over 
which the Board has control. Were- such a map of facts in existence 
the Rivers Conservancy Board, when appointed, would have a tangible 
foundation on which to improve their districts, increase its wealth, 
and preserve the health of its inhabitants. 
Whether it is advisable or necessary that there should be a 
responsible official of the crown in one of the Houses of Parliament, 
whose duty it should be to represent riparian requirements, is a 
matter almost beyond that of subjects appertaining to a scientific 
society, but that the necessity of control of our rivers should be 
vested in a representative body chosen from the district, and knowing 
its requirements, rests upon a scientific basis. 
Percolation of Rainfall into the Ground : — Experiments were 
made simultaneously by Dr. Dalton at Manchester, and by M. 
Maurier at Genoa, in the years 1796 to 1798. Dalton's guage was a 
cylinder 10 inches in diameter, and 3 feet deep, open at the top, 
closed at the bottom, filled with earth, and sunk into the ground 
