ON THE EARTHQUAKE PHENOMENA OF JAPAN. 379 
Earth Temperatures. 
In January a bore-hole was sunk in the grounds of the Imperial 
College of Engineering, about 100 feet in depth. The section, was 
approximately as follows :— 
Earthy materials and sand 78-0 shaku 
Very hard gravel . Dr as 
Fine gravel 20 5 
Sand Gas 
Gravel . i 5 5 OSes, 
Taff (a soft clay-like rock) £50.55 
Total» . . » 1040 ” 
The feet given are Japanese shaku (shaku = feet). On February 17, a 
series of thermo-electric junctions were lowered down the hole, one near 
the bottom, one at approximately 75 feet, another at approximately 50: 
feet, and a fourth at 21 feet. The bore-hole was then filled up by slowly 
pouring in from day to day a mixture of clay, sand, and water. The 
junctions consisted of thick iron and copper wires dipping into a glass. 
tube filled with mercury. All the copper elements had distinct cables 
leading to the surface. The iron elements at the different stations were 
joined to a single iron wire leading from the bottom to the top of the 
hole. The glass tubes were protected by brass tubes. All these junc- 
tions, together with a fifth junction buried just below the surface of the 
ground, can be compared with a similar junction in a water-bath in the 
Physical Laboratory. The whole of these arrangements are under the 
charge of Professor Fujioka, who at some future time will probably give 
some detailed account of his observations. The first records were made 
on March 26 and ran along steadily until April 16, when, for causes 
which are unknown, there was suddenly an increase in current, to balance 
which the water-bath had to be raised to a temperature about double 
that which had been required a few hours previously. 
The first portion of the observations are as follows :— 
T. 25 T. 50 T. 75 T. 100 
March26 . .| 240P.m./ 15°0C.| 16°4C. | 17°80. | 18°-000. 
4.0 ,, | 15°0 16°-2 18°-2 18°-10 
ear) so) 10.0 Sane | 15°-2 16°-2 18°-0 17°-80 
2.0 Pm. | 152 161 17°8 17°-10 
RIS: resi ade 8.80 AMs.|,15%-2 16°-1 17°'8 17°-20 
Met: wor . |. :80y %. 1 15°d 16°-1 17°-6 17°-00 
oot, . ..| 10:30 ,, 14°4 = 17°-0 16°-95 
weer 2 10:30" ,, 14°6 15°8 17°4 17°-40 
3.0 pm. | 15°-0 16°-0 17°-4 17°-80 
Rete, AM. bo 10.02 aten| 149-0 15°-2 17°-0 17°-80 
Be week esis dl “%, 14°°8 15°8 17°-4 16°-80 
BeeLD, . 5. < : 10:05 ss 14°-9 — nié=ta! 15°80 
