Years 

 Zones 



SCIENTIFIC SIDE-LIGHTS 



768 



seems shorter as we grow older that is, the 

 days, the months, and the years do so; 

 whether the hours do so is doubtful, and the 

 minutes and seconds to all appearance re- 

 main about the same. ... In youth we 

 may have an absolutely new experience, sub- 

 jective or objective, every hour of the day. 

 Apprehension is vivid, retentiveness strong, 

 and our recollections of that time, like those 

 of a time spent in rapid and interesting 

 travel, are of something intricate, multi- 

 tudinous, and long drawn out. But as each 

 passing year converts some of this experi- 

 ence into automatic routine which we hardly 

 note at all, the days and the weeks smooth 

 themselves out in recollection to contentless 

 units, and the years grow hollow and col- 

 lapse. JAMES Psychology, vol. i, ch. 15, p. 

 625. (H. H. & Co., 1899.) 



3794. YIELDING A BETTER PRO- 

 TECTION THAN HARDNESS Flexible 

 Buildings Best Withstand Earthquakes. 

 From [an examination of] the different 

 buildings found in earthquake countries, it 

 will be seen that if we wish to put up a 

 building able to withstand a severe shaking 

 we have before us structures of two types. 

 One of these types may be compared with 

 a steel box, which, even were it rolled 

 down a high mountain, would suffer but 

 little damage; and the other, with a wicker 

 basket, which would equally withstand so 

 severe a test. Both of these types may be, 

 to some extent, protected by placing them 

 upon a loose foundation, so that but little 

 momentum enters them at their base. 



One suggestion is to place a building upon 

 iron balls. The author found that the most 

 practical form of free foundation was to 

 rest the building upon layers of cast-iron 

 shot, each shot being about one-quarter inch 

 in diameter. Another method would be to 

 place them upon two sets of rollers, one set 

 resting upon the other set at right angles. 

 The sole-plates of a Japanese house rest 

 freely on more or less rounded stones. The 

 solid type of building is expensive, and can 

 only be approached partially, whilst the lat- 

 ter is cheap, and can be approached closely. 

 In the case of a solid building it would be 

 a more difficult matter to support it upon 

 a movable foundation than in the case of a 

 light framework. Such a [solid] building is 

 usually firmly fixed on the ground, and con- 

 sequently at the time of an earthquake, as 

 has already been shown by experiment, must 

 be subjected to stresses which are very great. 

 In consequence also of the greater weight of 

 the solid structure, the effects due to its own 

 inertia will be augmented. Also, we must 

 remember that the rigidity favors the trans- 

 mission of momentum, and with rigid walls 

 we are likely to have ornaments, coping- 

 stones, and the comparatively freer portions 

 forming the upper part of a building dis- 

 placed; whilst, with flexible walls, absorbing 

 momentum in the friction of their various 



parts, &uch disturbances would not be so 

 likely. MILNE Earthquakes, ch. 7, p. 127. 

 (A., 1899.) 



3795. 



Tracery of Fine 



Fabrics on Glass. By protecting certain 

 portions of the surface [of glass, from the 

 sand-blast], and exposing others, figures and 

 tracery of any required form could be etched 

 upon the glass. The figures of open iron- 

 work could be thus copied: while wire-gauze 

 placed over the glass produced a reticulated 

 pattern. But it required no such resisting 

 substance as iron to shelter the glass. The 

 patterns of the finest lace could be thus 

 reproduced; the delicate filaments of the 

 lace itself offering a sufficient protection. 

 All these effects have been obtained with a 

 simple model of the sand-blast devised by 

 my assistant. A fraction of a minute suf- 

 fices to etch upon glass a rich and beautiful 

 lace pattern. Any yielding substance may 

 be employed to protect the glass. By dif- 

 fusing the shock of the particle such sub- 

 stances practically destroy the local erosive 

 power. The hand can bear, without incon- 

 venience, a sand-shower which would pulver- 

 ize glass. Etchings executed on glass with 

 suitable kinds of ink are accurately worked 

 out by the sand-blast. In fact, within cer- 

 tain limits, the harder the surface the great- 

 er is the concentration of the shock, and the 

 more effectual is the erosion. It is not 

 necessary that the sand should be the harder 

 substance of the two; corundum, for exam- 

 ple, is much harder than quartz; still, 

 quartz-sand can not only depolish, but ac- 

 tually blow a hole through a plate of corun- 

 dum. TYNDALL Fragments of Science, vol. 

 i, ch. 7, p. 193. (A., 1897.) 



3796. YOUTH AND AGE, GEOLOG- 

 ICAL Such, then, are the several stages 

 through which a region of mountain-uplift 

 must pass. First comes the stage of youth, 

 when the surface configuration corresponds 

 more or less closely with the underground 

 structure. Next succeeds the stage of mid- 

 dle life, when such coincidence is all but 

 obliterated, when the valleys of youth have 

 been exalted and its mountains have been 

 laid low. Last comes old age and final 

 dissolution, when the whole region has been 

 reduced to its base-level. GEIKIE Earth 

 Sculpture, ch. 5, p. 125. (G. P. P., 1898.) 



3797. YOUTH THE PERIOD FOR 

 FORMING PERSONAL HABITS Character 

 Plastic before Twenty. If the period be- 

 tween twenty and thirty is the critical one 

 in the formation of intellectual and pro- 

 fessional habits, the period below twenty 

 is more important still for the fixing of 

 personal habits, properly so called, such as 

 vocalization and pronunciation, gesture, mo- 

 tion, and address. Hardly ever is a lan- 

 guage karned after twenty spoken without 

 a foreign accent; hardly ever can a youth 

 transferred to the societv of his betters un- 



