Oct. 26, 1882] 



NATURE 



627 



table-lands, in determining the continuance and the direc- 

 tion of the course of cyclones ; and the influence of 

 isolated mountains and mountainous ridges in breaking 

 up a cyclone into two distinct cyclones, which, from 

 the difficulty necessarily experienced by seamen in inter- 

 preting the complex phenomena attending them, often 

 prove so destructive in their effects. 



SEISMOLOGY IN JAPAN 



THE first earthquake that I ever felt took place about 

 2 a.m. on the night of April 10, 1876. On this night, 

 which was soon after my arrival in Yedo, I had been in- 

 stalled in a new house. To be absolutely alone in a large 

 partially furnished dwelling in a strange land, and then 

 in the dead of night to be wakened by a swinging motion 

 of the bedstead, a rattling of windows, creaking of timbers, 

 and flapping of pictures was more than bewildering. 



For some time after the motion had died away, which 

 motion had several maxima and minima, some little rings 

 upon the bedstead which had been caused to swing, kept 

 up a gentle clicking, and a night light upon a basin of oil 

 as it swayed from side to side cast long flickering shadows 

 across the room. The general behaviour of things was 

 ghostly, and it was some time before I could assure 

 myself that what I had experienced was an earthquake. 



Next morning, however, my doubts were dissipated by 

 my neighbours making jocular inquiries about the nature of 

 my experiences. Earthquake conversation, I may remark, 

 is often used in Yedo to fill up the gaps in conversation, 

 which in England are usually stopped by queries and 

 truisms about the weather. This was my first earthquake. 



Palmieri's instrument indicated that its direction was 

 about E.S.E. to W.N.W., and its force was 6 degrees. 

 By 6 degrees is meant that the shaking caused some 

 mercury contained in a glass tube to wash up and down 

 until a little string attached to an iron float on its surface 

 had turned a pullyand a pointer through 6°. By observing 

 the tables of these indications it is seen that a very gentle 

 shaking of long duration may get up a violent oscillation 

 in the mercury and so indicate a shock of a great number 

 of degrees, whilst a violent sharp shock, which might knock 

 over a chimney, may possibly only indicate a few degrees. 



Since my first earthquake I have had the opportunity 

 during the last six years of studying rather more than 

 400 other shakings. One of these shook d jwn chimneys, 

 unroofed houses, twisted gravestones, and by its action 

 generally entitled itself to be called destructive and alarm- 

 ing. The effect that this earthquake produced upon the 

 nerves of many people was quite as great as that which 

 might be produced upon children with an imaginary ghost. 

 As residents in Japan are so often alarmed by earthquakes 

 it is only natural that they should be led to study these 

 phenomena. Amongst the first instruments which were 

 employed for their investigation were, as might be antici- 

 pated, small columns, bowls of liquid, and other con- 

 trivances, which are found described in books and papers 

 treating of observational seismology. 



Columns which have been made of various shapes 

 and various materials have been found unsatisfactory, 

 because it is seldom (even when a house may be sway- 

 ing violently), if they are on a stone platform firmly 

 fixed to the ground that they are overturned. When 

 it happens that they are overturned, if there were 

 several columns side by side you would usually find 

 them lying pointing like the arms of a star-fish in different 

 directions. If an earthquake was a sharp blow, no doubt 

 the columns would fall in the direction of the shock and 

 also towards the point from which the shock came. 

 Yedo earthquakes, however, commence gently, and the 

 column is caused to rock before it falls, and as it rocks 

 its plane of rocking may be gradually changed. Another 

 explanation would be that some of the columns had fallen 

 with direct shocks and some with reflected shocks, or 



that some were overturned with the normal and some 

 with the succeeding transverse vibrations. 



Bowls of liquid have been found impracticable ; first, 

 because it is seldom that in a bowl on a firm foundation 

 a sufficiently measurable amount of washing up is ob- 

 tained ; and second, that any of the usual methods of 

 registering the motion as well as many other methods, 

 both chemical and mechanical which have been tried, are 

 not satisfactory. Also there are the difficulties of freezing 

 and evaporation to contend with. 



Similarly the records of the old-fashioned ordinary 

 pendulum with a pointer resting in sand, or, what is 

 perhaps better, provided with a sliding pointer writing 

 over a smoked glass plate, are also very unsatisfactory. All 

 that many of the carefully drawn records produced by 

 swinging pendulums appear to indicate, is that there has 

 been an earthquake, and it has caused the pendulum to 

 swing about. For reasons like these, after considerable 

 experience the conclusion arrived at is that the records of 

 most of the older forms of seismographs and seismo- 

 meters, of which legions have been experimented with, 

 can only be regarded as being seismoscopic. 



When we look into the history of observational seismo- 

 logy, and take the following description of a seismometer 

 invented nearly 1800 years ago as a standard of com- 

 parison between the old and better known forms of 

 earthquake instruments for registering ordinary shocks, 

 it is doubtful whether this branch of earthquake investi- 

 gation has been much advanced. This description was 

 given to me by Mr. J. Hattori, vice-director of the Im- 

 perial University. It was translated for me by my 

 assistant, Mr. M. Kuwabara. It runs as follows : — 



In a Chinese history called " Gokanjo," we find the 

 following : "In the first year of Yoka (a.d. 136) a Chinese 

 called Chioko invented a seismometer. This instrument 

 consists of a spherically formed copper vessel (Fig. 1), its 

 diameter being 8 ' shaku.' It is covered at its top. Its form 

 resembles a wine bottle. Its outer part is ornamented with 

 the figures of different kinds of birds and animals and 

 old peculiar looking letters. In the inner part of this 

 instrument a pillar is so placed that it can move in eight 

 directions. Also in the inside of this bottle there is an 

 arrangement by which some record of an earthquake is 

 made according to the movement of the pillar. On the 

 outside of the bottle there are eight dragon heads, each 

 of which contains a ball. Underneath these heads there 

 are eight frogs, so placed that they appear to watch the 

 dragon's face, so that they are ready to receive the ball if 

 it should be dropped. All the arrangements which cause 

 the pillars when it moves to knock the ball out of the 

 dragon's mouth are well hidden in the bottle. When an 

 earthquake occurs and the bottle is shaken, the dragon 

 instantly drops the ball, and the frog which receives it 

 vibrates vigorously. Any one watching this instrument 

 can easily observe earthquakes. With this arrangement, 

 although one dragon may drop a ball, it is not necessary 

 for the other seven dragons to drop their balls unless the 

 movement has been in all directions ; thus one can easily 

 tell the direction of an earthquake. Once upon a time a 

 dragon dropped its ball without any earthquake, and the 

 people therefore thought that this instrument was of no 

 use, but after two or three days a notice came saying that 

 an earthquake had taken place in Rosei. Hearing of 

 this, those who did not believe about the use of this 

 instrument began to believe in it again. After this in- 

 genious instrument had been invented by Chioko, the 

 Chinese Government wisely appointed a secretary to 

 make observations on earthquakes.'' 



We have here I think not only an account of an earth- 

 quake instrument which in principle is identical with 

 many of our modern inventions, but the science has been 

 conjoined with art. The record of the Chinese Govern- 

 ment establishing a seismological bureau at a time when 

 America was unknown, and half of Wes'ern Europe were 



