504 NATURE | Sepz. 24, 1885 
chalk. From the bottom of the well a 24-inch bore-hole was | lower part of the bore prevents any downward convection of 
sunk to the total depth of 434 feet, thus penetrating 181 feet into 
the chalk. This portion of the work was completed in 1877. 
Above the chalk were tertiaries, consisting of 160 feet of Lon- 
don clay, 60 feet of the Woolwich and Reading beds, and some 
underlying sands. The water yielded at this stage was about 
160 gallons a minute, and, when not depressed by pumping, was 
able to rise 4 or 5 feet above the surface. Its ordinary level, 
owing to pumping, was about 130 feet lower. In 1881 the Rich- 
mond Vestry determined to carry the bore-hole to a much 
greater depth, and the deepening has been executed under the 
direction of Mr. Homersham. The existing bore-hole was first 
enlarged and straightened, to enable a line of cast-iron pipes, 
with an internal diameter of 16} inches, having the lower end 
driven water-tight into the chalk at a depth of 438 feet, to be. 
carried up to the surface. The total thickness of the chalk was 
671 feet. Below this was the upper greensand, 16 feet thick ; 
then the gault clay, 2013 feet thick; then ro feet of a candy 
rock, and a thin layer of phosphatic nodules. Down to this 
point the new boring had yielded no water. Then followed a 
bed 874 feet thick, consisting mainly of hard oolitic limestone. 
Two small springs of water were met with in this bed at the 
depths of 1203 and 1210 feet, the yield at the surface being 1} 
gallons a minute, with power to rise in a tube and overflow 49 
feet above the ground. A partial analysis of this limestone 
rock showed it to contain 2°4 per cent. of sulphide of iron in 
the form of pyrites. At the depth of 1239 feet this limestone 
rock ended, and hard red sandstone was found, alternating with 
beds of variegated sandy marl or clay. After the depth of 1253 
feet had been attained, the yield of water steadily increased as 
the boring was deepened, the overflow at the surface being 2 
gallons a minute at 1254 feet, 8 gallons at 1363 feet, and 11 
gallons at 1387 feet. It rose to the top of a tube carried 49 feet 
above the surface, and overflowed ; and a pressure-gauge showed 
that it had power to rise 126 feet above the surface. The 
diameter of the bore was 16} inches in the chalk, 133 inches in 
the gault, 11} inches in the oolitic limestone, and at the depth 
of 1334 feet it was reduced to a little under 9 inches. At 1337 
feet the method of boring was changed, and, instead of an 
annular arrangement of steel cutters, a rotary diamond rock- 
boring machine was employed. The bore-hole, with a diameter 
of 8} inches, was thus carried down to 13674 feet, at which 
depth, lining tubes having to be inserted, the diameter was re- 
duced to 7{ inches, and this size was continued to 1447 feet, at 
which depth the boring was stopped. The bore-hole was lined 
with strong iron tubes down to the depth of 1364 feet ; and 
those portions of the tubes that are in proximity to the depths 
where water was struck were drilled with holes to admit the 
water into them. Three observations of temperature taken 
with an inverted Negretti maximum at the depth of 1337 
feet, awhen the bore-hole was full of water, recorded 
752 FE. In the first observation, March 25, 1884, the ther- 
mometer was left for an hour and a quarter at the bottom 
of the bore-hole, and three weeks had elapsed since the water 
was disturbed by boring. The second observation was taken on 
March 31, when the thermometer was 54 hours at the bottom. 
In the third observation special precautions were taken to pre- 
vent convection. The thermometer was fixed inside a wrought- 
iron tube, 5 feet long, open at bottom. The thermometer was 
near the lower end of the tube, and was suspended from a 
water-tight wooden plug, tightly driven into the tube. There 
was a space of several inches between the plug and the ther- 
mometer, and this part of the tube was pierced with numerous 
holes to allow the escape of any cold water which might be 
carried down by the tube. The tube was one of a series of 
hollow boring-rods used in working the diamond drill-machine. 
By means of these it was lowered very slowly, to avoid disturb- 
ance of the water as much as possible ; and the tube containing 
the thermometer was gradually worked through the sand at the 
bottom of the bore-hole. The lowering occupied five hours, 
and was completed at noon on Saturday, June 7. Cement, 
mixed with sugar, for the purpose of slow setting, was imme- 
diately lowered on to the surface of the sand, and above this a 
mixture of cement and sand, making a total thickness of 3 or 4 
feet of cement plugging. The thermometer was left in its place 
for three full days, the operation of raising being commenced at 
noon of Tuesday, June 10, and completed at 5 p.m. The 
thermometer again registered 754° F., exactly the same as in the 
two previous observations which were taken without plugging. 
It would therefore appear that the steady upflow of water in the 
colder water from above. 
The boring has since been carried to the depth of 1447 feet, 
with a diameter reduced to 7} inches, and Mr. Homersham 
lowered the thermometer to the bottom without plugging. It 
remained down for six days (February 3 to 9, 1885), and gave 
a reading of 763° F. The water overflowing at the surface had 
a temperature of 59° F. To deduce the mean rate of increase 
downwards, we shall assume a surface temperature of 50°. This 
gives for the first 1337 feet an increase of 254°, which is at the 
rate of r° F. in 5274 feet, and for the whole 1447 feet an increase 
of 262°, which is at the rate of 1° F. in 54‘1feet. These results 
agree well with the Kentish Town well, where Mr. Symons 
found in 1100 feet an average increase of I° in 55 feet. 
Mr. Galloway has furnished observations taken during the 
sinking of a shaft to the depth of 1272 feet in or near the Aber- 
dare valley, Glamorganshire. The position of the shaft is on 
the slope on the east side of the valley, about midway between 
the bottom of the valley and the summit of the hill which 
separates it from the Merthyr valley. The mouth of the shaft is 
about 800 feet above sea-level. Observations were taken at 
four different depths—546 feet, 780 feet, 1020 feet, and 1272 
feet—the thermometer being in each case inserted, and left for 
twenty-four hours, in a hole bored to the depth of 30 inches at a 
distance not exceeding 24 yards from the bottom of the shaft for 
the time being. About eight hours elapsed between the com- 
pletion of the hole and the insertion of the thermometer. The 
strata consist mainly of shales and sandstone, with a dip of 1 in 
12, and the flow of water into the shaft was about 250 gallons 
per hour. The first of the four observations was taken in the 
fireclay under the Abergorkie vein ; the second in strong “‘ clift ” 
(a local name for argillaceous shale) in disturbed ground ; the 
third in bastard fireclay under a small rider of coal previously 
unknown ; the fourth in ‘‘clift”” ground two yards above the 
red ash vein, which overlies the 9-foot seam at a height of from 
9 to 12 yards. The observations were as follow :—At 546 feet, 
56° F. ; 780 feet, 594° F. ; 1020 feet, 63° F. ; 1272 feet, 664° F. 
Comparing consecutive depths from 546 feet downwards, we 
have the following increments of temperature :—3}° in 234 feet, 
giving 1° for 67 feet ; 3° in 240 feet, giving 1° for 69 feet ; 33° in 
252 feet, giving 1° for 72 feet ; showing a remarkably regular 
rate of increase. A comparison of the first and fourth observa- 
tions gives an increase of 104° in 726 feet, which is at the rate of 
1° F. in 69'1 feet. As a check upon this result we find that 
this rate of decrease reckoned wpwards from the smallest depth 
(546 feet) would give a surface temperature of (56—7°9=) 48°"I, 
which, as the elevation is 800 feet, is probably very near the 
truth. 
Mr. Garside has sent an observation of temperature taken by 
himself in the roof of the Mersey tunnel in August, 1883. The 
temperature was 53°, the depth below Ordnance datum being 
92 feet. A great quantity of water from the river was percolat- 
ing through the sides of the tunnel. On August 13, 1854, he 
verified his previous observation in Denton Colliery (15th 
Report). The second observation was made at the same depth 
as the first (1317 feet), in the same pit and level, and under the 
same circumstances, except that the thermometer was allowed 
to remain fourteen days in the hole bored for it, instead of only 
six hours. The temperature observed was the same as before— 
namely 66°, Mr. Garside has also supplemented his previous 
contribution to our knowledge of the surface temperature of the 
ground in the East Manchester coal-field (16th Report) by two 
more years’ results from the same observing stations. The differ- 
ence between them agrees well with the generally accepted rate 
of 1° for 300 feet, and indicates about 48° as the surface tempe- 
rature at small elevations, such as 30 feet. The pits in the East 
Manchester coal-field from which we have observations—namely, 
Astley Pit (Dukinfield), Ashton Moss, Bredbury, Denton, and 
Nook Pit, are all sunk in ground at elevations of between 300 
and 350 feet. It would therefore appear that the assumption of 
a surface temperature of 49°, which we made in reducing these 
observations, is about 2° in excess of the truth. A very elaborate 
paper on ‘* Underground Temperature ’”’ has recently been com- 
municated to the Royal Society by Prof. Prestwich. He is 
disposed to adopt 1° F. in 45 feet as the most probable value 
of the normal gradient. 
Report of the Committee, consisting of Mr. W. T. Blanford 
and Mr. F. S. Gardner (Secretary), on the Fossil Plants of the 
Tertiary and Secondary Beds of the United Kingdom. Drawn 
