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THE POPULAR SCIENCE MONTHLY. 



no trace of them upon an exhaustive search. 

 He concludes that the animals must wander 

 farther from their breeding-grounds than is 

 supposed, or else must dig far deeper into 

 the earth than to six or eight inches, as 

 stated by Holbrook and De Kay. 



Effect of Earthquakes on Buildings. 



Mr. John Milne, of Tokio, Japan, has pub- 

 lished some observations of the effects of 

 earthquakes on buildings. In regard to the 

 relative security of buildings on low and on 

 high ground there is no universal rule, but 

 each small area in an earthquake-region has 

 its peculiarities. Theory indicates that soft, 

 marshy ground is safer, because it will act 

 as a buffer between the shock and the build- 

 ing ; and the Temple of Diana, at Ephesus, 

 was located with reference to this point. 

 But experience at Tokio and Manila has 

 shown repeatedly that there is very little, 

 if anything, in it ; and hard, rocky strata, 

 where the amplitude of motion is small, but 

 the period quick as compared with the mo- 

 tion in the inelastic material of the plains, 

 proved the better foundation in Jamaica in 

 1692, and at Lisbon in 1755. Places to be 

 avoided are the edges of cliffs, scarps, and 

 cuttings. Europeans fasten the foundations 

 of their buildings firmly in the ground, and 

 their houses are much shaken. The Japa- 

 nese put their structures loosely on top of 

 stones or bowlders, and they escape seri- 

 ous disturbance. Europeans and Americans 

 build iron-bound houses to resist earth- 

 quakes, and they resist them, though they 

 get badly shaken, as a steel box would be ; 

 but they are very expensive. The Japanese 

 and the people of the west coast of South 

 America build a kind of wicker - basket 

 house a frame house with a light roof, 

 which lives through the earthquake like "a 

 reed shaken by the wind." The stability of 

 such houses depends upon their not being 

 firmly attached to the earth, and their nu- 

 merous joints admit considerable yielding, 

 so that the earthquake-wave passes through 

 them before they begin to show its visible 

 effects. A cheap aseismic house would be 

 a low frame building supported by a num- 

 ber of slightly concave surfaces resting on 

 segments of stone or metal spheres in con- 

 nection with the ground. Chimneys should 

 be given a play-space around them, and not 



be in contact with the roof ; else, since the 

 vibrational periods of the chimney and the 

 roof never correspond, clashes will occur 

 between them, and a shock and overthrow 

 result. The pitch of the roof should not be 

 great, or the tiles or slates will be shot off ; 

 and the upper parts of all buildings should 

 be as light as is consistent with strength. 



Suggestions in School-keeping. Mrs. 

 H. F. Wilson, in a paper read before the 

 Educational Association of Alabama, tells 

 how in her school she eschewed the system 

 of marks and statistical reports as pernicious 

 and false, and imposed as the one rule to 

 govern the whole school, " Do right " ; and, 

 as the real goal to be reached, excellence in 

 everything. Incorrect sentences heard by 

 any pupil are reported in a blunder-box, to 

 be corrected by the school. Once a week, 

 half an hour is devoted to the recitation of 

 facts, drawn from the public press and 

 other sources. Half of every holiday is 

 given to microscopic, stereoscopic, or other 

 instructive exhibitions. In connection with 

 the teaching of music, information is col- 

 lected concerning the old masters of music. 

 Physical culture is attended to, and dancing 

 is cultivated as an element of it. In this 

 work the teacher finds infinite variety and 

 enjoyment, and has been " filled with amaze- 

 ment and enthusiasm at the immense amount 

 of work pupils did unbidden, hunting over 

 cyclopaedias and books of reference for in- 

 formation when the text-book was obscure 

 or inadequate." 



Source of Atmospheric Electricity. 



The source of atmospheric electricity has 

 never yet been satisfactorily indicated, al- 

 though various theories have been suggested 

 to account for it. It has been attributed to 

 aerial friction, to combustion or oxidation, 

 to evaporation, and to condensation, to in- 

 ductive or conductive effects of the earth's 

 electricity, to convection currents, to electri- 

 fied corpuscles coming from the sun, to solar 

 radiation, to the friction of aqueous vapor 

 against dry air, to capillary surface-tension 

 of water, to the production of hail, etc. 

 Professor Tait suggests that the mere con- 

 tact of the particles of vapor with the air 

 may suffice to produce the exceedingly small 

 potential requisite to start the effects. He 



