NovembekS, 1900.] 



SCIENCE. 



679 



damage to buildings and other structures, as far 

 as may be found possible, so that much attention 

 has been given to studies of resistance of 

 materials of construction and to the effect of 

 actual earthquakes upon existing structures of 

 various kinds. No. 3 consists, in the main, 

 of an account of a most elaborate and in- 

 teresting experimental investigation of some 

 of the more important physical properties of 

 bricks, and briquettes of cement, mortar, etc., 

 especial attention being given to those qualities 

 which give strength and stability against seismic 

 disturbance. This report is by S. Tanabe, a 

 member of the Committee, and is a valuable 

 contribution to our knowledge of the subject. 



There is also, in the same volume, a short 

 description by B. Mano of a machine by which 

 a platform or ' shaking table ' is made to 

 oscillate as it would during the passage of a 

 series of seismic waves, the horizontal and 

 vertical motions being produced independ- 

 ently, each capable of adjustment as to ampli- 

 tude and frequency, so that almost any kind of 

 disturbance may be imitated, except minute 

 earth ' tremors.' The motive power consists of 

 two steam engines, and as many as 270 oscilla- 

 tions per minute may be maintained. There is 

 also a brief note on the damage suffered by tall 

 chimneys in the earthquake of June, 1894, and 

 in that of October, 1893. In the case of the 

 latter 230 chimneys in all were examined, rang- 

 ing in height from 30 feet to 150 feet. Of 

 these 53 suffered serious injury, the highest per- 

 centage being for those between 60 feet and 80 

 feet high. The volume closes with a paper in 

 English on ' The Scope of the Volcanological 

 Survey in Japan,' by Dr. B. Koto, member of 

 the Committee, who has undertaken to study 

 the geological aspects of the seismic problem. 

 For the great majority of earthquakes the 

 author rejects the volcanistic hypothesis and 

 adopts the tectonic, believing that seismic dis- 

 turbances are Intimately related to the process 

 of mountain building. 



No. 4 begins with a condensed statement 

 on the ' Construction of Earthquake-proof 

 Wooden Buildings.' Although very brief, this 

 paper is of great interest, and as nearly all 

 houses in Japan are built of wood it must prove 

 to be of great practical value. Rules for the 



making of joints, the construction of frame 

 work and especially of roof framing are given 

 with sufiScient detail and clearness (aided by 

 numerous illustrations), and particular emphasis 

 is placed on the character of the foundation. 

 Even ordinarily constructed wooden houses 

 are damaged less by earthquake disturbances 

 than structures of brick or stoue, and when 

 built according to the rules and suggestions 

 given in this paper they will be generally im- 

 mune except during unusually violent shocks. 

 The worst part of an ordinary Japanese house, 

 from the seismic standpoint, is the heavy 

 tile roof, and the importance of making the 

 roof as light as possible, and of having the 

 tile securely fastened, is dwelt upon in this 

 compendium. The use of iron plates and 

 straps, with bolts, in the formation of joints is 

 strongly advised. It may be interesting to 

 note here that the new palace for the use of the 

 Prince Imperial is to be a modern ' structural 

 steel ' affair, the material having been obtained 

 in this country, and in the structural plans, 

 made by American architects, especial care has 

 been exercised to provide against damage by 

 earthquake. By the use of numerous cross- 

 braces and ' ties ' it is made to resemble some- 

 what a huge steel basket which, although it 

 may, and indeed, should be capable of a little 

 elastic yielding, can never be seriously injured 

 in any imaginable seismic disturbance. 



Anent the generally damaging effect of 

 earthquakes upon brick buildings Dr. F. Omori 

 discusses the records of a number of disturb- 

 ances as shown by two of Professor Ewing's 

 horizontal pendulum seismographs, one of 

 which was set up on a wall of a large brick 

 building, known as the Engineering College, 

 and the other on the ground near by. Ten 

 earthquakes were thus observed and recorded, 

 none being very strong. The results appear to 

 show that in comparatively long period oscilla- 

 tions, that is to say those somewhat above .5 

 second, there was no noticeable difference in 

 amplitude between those of the second story of 

 the brick building and those of the ground, 

 while with quick period motions the movement 

 was greater on the wall of the building than 

 on the ground, the average amplitude of the 

 former being double that of the latter. Omori 



