MISCELLANY 



763 



Tolves use of nerves. The external force, 

 if exerted by a muscle, is only part of that 

 which it produces. Now, the proportion 

 between these two in their several degrees 

 is a subject of great practical importance, 

 and some interesting facts have recently 

 been published by Ilelmholtz. From these 

 it is clear that the greater the external force 

 exerted the greater is the proportion of the 

 needful internal force that is, great exer- 

 tion is more wasteful than moderate exer- 

 tion. Then force has to be evolved in pro- 

 portion to the external work done, and 

 therefore the greater is the wear and tear 

 of the animal machine. The same increased 

 proportion of non-productive work is seen 

 when the external energy is below a moder- 

 ate amount. It is found, for instance, that 

 in walking, a speed of three miles an hour 

 gives the most economical use of the forces. 

 No doubt in these facts we have an index 

 to much of the ill effects of the present 

 high-pressure rate of work and life. The 

 waste of force is out of proportion to the 

 work done. More is effected in a given 

 time, but the body feels it more, and its 

 working period is proportionately shorter. 

 These facts cannot be too often repeated or 

 too constantly remembered by those who 

 have the regulation of labor. Lancet. 



ContribntioDs to Meteorology. The 



American Journal of Science, for January, 

 contains the fourth paper by Prof. Loomis, 

 giving results of recent researches in the 

 science of meteorology, founded on data 

 derived chiefly from the weather-maps of 

 the United States Signal Service. 



In a former article attention was called 

 to the fact that low temperatures at the 

 surface of the earth are produced by de- 

 scent of cold air from the upper regions of 

 the atmosphere. It was shown that, in areas 

 of high barometer, tlie movement of the 

 air is outward from the centre, instead of 

 inward, as in case of low barometer or 

 storm. This implies a supply from down- 

 ward motion. 



The current notion, that extreme cold is 

 brought by wind from colder areas, is met 

 by the fact that, at Yakootsk, in Siberia, 

 which is about the coldest place in the 

 Northern Hemisphere, the temperature is 

 lowest when the air is quite still, and equal- 

 ly when the wind is from north, south. 



east, or west. These results are obtained 

 from four years' observations at that place, 

 and are similar to those obtained at New 

 Haven, except as to direction of wind. It 

 would be diificult to explain where the ex- 

 treme cold of Yakootsk came from, except 

 from the upper atmosphere, seeing that it 

 is colder than the country round about. 



A diurnal variation in the progress of 

 storms was noticed by Prof. Loomis in a 

 former paper. This fact suggested to him 

 the further one that there is a diurnal ine- 

 quality in the rainfall. This is now shown 

 by observations made at Philadelphia, not 

 by the Signal Service maps, which do not 

 record hourly observations. It appears 

 that the maximum rainfall occurs at about 

 six o'clock in the afternoou ; and the mini- 

 mum at three o'clock in the morning. 



By observations which cover a peiiod of 

 ten years, made at Prague, in Bohemia, it 

 appears that the greatest rainfall during the 

 day occurs in the afternoon, the maximum 

 being from three until six o'clock. 



The tracks of storms in America and Eu- 

 rope, already noticed by Prof. Loomis, are 

 further considered in this paper. He de- 

 termined the precise latitude at which the 

 storm-centres cross certain lines of longi- 

 tude, and in this way establishes a line 

 which is the track of the storm-centre ; a 

 similar method was applied to storms in 

 Europe. It appears that the average track 

 is not regular, but varies. In an article 

 published in July, ISH, it was stated that 

 the average direction of the storms of the 

 United States was, for the year, 8 north of 

 east, and that is correct as a general state- 

 ment. Connected with the present arti- 

 cle is a chart, by which it is seen that the 

 average track of American storm-centres is 

 over Chicago and Detroit, and is deflected 

 to the south coast of Newfoundland. From 

 this point it seems to be continuous over 

 the ocean, being deflected northward near 

 the Irish coast, passes over Dublin, and 

 thence across Denmark. These results, 

 however, are obtained from the Paris maps, 

 and the continuity of the line may, in some 

 measure, depend on the extent of the field 

 of observations by which it was determined. 



The number of storms traced across the 

 Atlantic Ocean is not large ; they undergo 

 changes on the ocean, and frequently are 

 merged in other storms. 



