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THE POPULAR SCIENCE MONTHLY. 



becomes definite, for all the loads are sure 

 to be concentrated at the column centers 

 that carry them. Kindred to this change is 

 the large independence of partition walls 

 which the steel construction makes possible. 

 Another radical change, and the most con- 

 spicuous to the eye that steel has introduced, 

 is in the height of large buildings. Steel 

 buildings their construction admitting of 

 unlimited bracing may be carried to any 

 height, the only restrictions being those im- 

 posed by the character of the foundations, 

 the land, and economical considerations. The 

 steel construction admits a vast increase of 

 window space, the masonry walls which had 

 to be built for strength being no longer re- 

 quired, and their place may be taken by 

 glass. 



The Weather and Mental Aetion. Who 



has not felt the difference between a de- 

 pressing and an exhilarating day? Sydney 

 Smith wrote : " Very high and very low tem- 

 peratures establish all human sympathy and 

 relations. It is impossible to feel affection 

 above seventy-eight degrees or below twenty 

 degrees." Dr. Fair and Dr. Stark almost 

 lead us to think morality is registered on the 

 thermometer, so surely does it measure cer- 

 tain kinds of criminality. On suicides the 

 effects of the weather are well known. 

 Nearly all vocations are affected by weather. 

 Men of science are often as much subject to 

 weather as seamen. Some writers must have 

 the weather fit the mood, character, or scene. 

 If one will read poetry attentively, he will 

 be surprised to find how many weather marks 

 are scattered through it. Diverse weather 

 states may be one cause of so much diversity 

 and even disagreement in thought processes 

 usually regarded as scientific. Many experi- 

 enced teachers think there should be modi- 

 fications of school work and discipline to 

 correspond with the weather. The head of a 

 factory employing three thousand workmen 

 has said, " We reckon that a disagreeable 

 day yields about ten per cent less work than 

 a delightful day, and we thus have to count 

 this as a factor in our profit and loss ac- 

 count." These are some of the ideas put 

 forth in a preliminary statement by J. S. 

 Lemon, who proposes to publish more at 

 length upon the subject. "Laboratory in- 

 vestigation of the subject," he says, " meets 



at the outset the difficulty of distinguishing 

 results of weather changes from similar states 

 otherwise caused. This difficulty is no greater 

 than in many other topics of research, and 

 we believe will not invalidate our methods 

 and results." 



Characteristics of Recent Geological 

 Stndy. If one were asked, says Sir Archi- 

 bald Geikie, to specify the feature which 

 above all others has marked the progress of 

 geology in Britain during the past five and 

 twenty years, he would reply, the enlarged 

 attention given to the study of the rocks, or 

 petrography ; and this study has been revo- 

 lutionized by the introduction of the micro- 

 scope as an adjunct to research. The rocks 

 of the country have become a foremost ob- 

 ject of study. In stratigraphical geology a 

 much closer attention than ever before has 

 been given to the investigation of the most 

 ancient accessible parts of the earth's crust. 

 The fundamental platform on wdiich the fos- 

 siliferous rocks repose has been searched for 

 and has been detected in several places 

 where it was not before supposed to exist. 

 We know more clearly than before the gen- 

 eral outlines of two or more great geological 

 periods anterior to the earliest relics of ani- 

 mal life. Among the applications of pale- 

 ontology to the stratigraphical side of geology 

 the most important in recent times has been 

 the recognition of life zones among the 

 stratified formations and the adoption of 

 these as a clew to the interpretation of the 

 sequence of strata, and even under some risk 

 of error of tectonic structure. In the de- 

 partment of geotectonics one of the most 

 interesting features has been the increased 

 attention bestowed upon the nature and 

 results of the great movements that have 

 affected the crust of the earth. Another 

 distinguishing characteristic of the period 

 has been the increased interest taken in the 

 history of the earth's surface or its super- 

 ficial topography as contrasted with the al- 

 most exclusive attention given by the older 

 geologists to the story of the rocks. The 

 views respecting the possible age of the 

 earth have undergone several modifications 

 by geologists and physicists alternately, with 

 accepted periods ranging from four hundred 

 millions down to ten millions of years. The 

 latest phase of them is that put forward by 



