120 REPORT— 1895. 



During the few weeks it was used, it showed a small but regular diurnal 

 fluctuation, being farthest north about 3 or 5 P.M., and farthest south 

 between 9 a.m. and noon (fig. 12, p. 137). 



Pendulum at P. — Sensibility about the same as N. The instrumeat 

 used at this station was the same as that used at N and K. 



The hut faced an open space about 70 yards square on its northern 

 side, but on all other sides it was shaded by high trees. For one or two 

 hours about mid-day a few rays of sunshine reached the roof of the hut 

 and the northern side of the open space. That the ground within 20 or 

 30 yards of the hut had but little sunshine may be inferred from the fact 

 that after a fall of snow this remained upon the ground for ten or fifteen 

 days. On open ground the snow disappeared in two or three days. 

 During the day this would slightly thaw upon its surface, and at night it 

 would freeze. About 50 yards to the east, a bluff' sloped down to the 

 Tokio plain. 



Observations were only made between January 14 and February 4. 

 The movements were extremely irregular, the most peculiar happening 

 between January 14 and January 26. On these days, excepting the 23rd 

 and 25th, during the night the pendulum made a rapid excursion towards 

 the east, returning to its normal position some time about noon on the 

 following day. These abnormal movements took place upon nights when 



~1 



Fig. 2. 



i.Joprrv Joji 13 1Z]5^^ ~ — ^^j/>7t ^j 



s^ , \ XxLuit cfnwremtnJt 



z 2c a m- 



Jan. /3 m95 



EasbA'anU is imMjwn'n 



it was unusually cold, and therefore they may have been due to the freez- 

 ing of moisture beneath or in the vicinity of the column (fig. 2). 



Pendulum at Q. — This instrument, which is in charge of the Meteoro- 

 logical Department, is as well installed as the pendulum at A. It stands- 

 on a stone column in a dark room in the same building with a self- 

 recording electrometer. The boom, which at first was partly made of 

 lacquered bamboo, but which has been replaced by one of aluminium,, 

 points from north to south. Immediately outside the room there is one- 

 of the castle walls sloping down to a deep moat, beyond which comes the 

 plain of Tokio. 



The diurnal movements are slight, but decided, the westerly excur- 

 sion being completed at from 3 to 6 p.m., and the easterly at about 6 a.m., 

 wliich corresponds to the motions at J and K. Tremors are slight. 



Pendidnm at R. — This pendulum was set up in a hut in the garden at 

 No. 17, Kaga Yashiki, Tokio. At a distance of about 5 yards on its 

 western side a steep bank leads down to a road, which joins a second road 

 at right angles on the north side of the hut, about 30 feet below the level 

 of the garden. 



The instrument is intended to act as a seismograph, sensitive to slight 

 vibratory motions, while from the length of its boom, which is about 

 3 feet, it is also able to record slight changes in level. The first 2 inches 

 of the boom is a small metal tube, at one end of which there is an agate 

 cup. This boom is continued by a reed, at the end of which there is a 



