122 



POPULAR SCIENCE NEWS. 



[August, 1889. 



while ill winter it is tunieil I'artlier away, aiui 

 the more obliiiiie heat rays arte unable to raise 

 the temperature to any great degree. The 

 varying length of the days is also an impor- 

 tant clement, as the long days of summer 

 allow the earth to be exposed for a longer 

 time to the influence of the source of heat. 



The thermal summer — that is, the period 

 of greatest heat — does 'not correspond with 

 the astronomical summer. On June 21st the 

 sun's rays are most nearly vertical, and the 

 earth is exposed to their influence for a 

 greater proportion of the twenty-four hours, 

 but the hottest weather is not, generally expe- 

 rienced till about a month later, and, similarly, 

 the greatest cold does not occur until after the 

 winter solstice. A certain amount of time is 

 necessary for the increasing heat of the 

 approaching summer to counteract the cold 

 of the preceding winter, and vice versa. A 

 similar delay is noticed in the daily fluctua- 

 tions of temperature ; the hottest part of the 

 day is not at noon, but about three o'clock, 

 while the lowest temperature of the night is 

 reached in the early morning hours. 



As might be expected, the highest temper- 

 atures of summer are accompanied b}' south- 

 erly or southwesterly winds, blowing from 

 the heated lands to the south of us, or from 

 the tropical waters of the Gulf of Mexico. 

 The oppressive nature of this heat is largely 

 due to the high percentage of moisture which 

 the air contains. This tends to check the 

 insensible perspiration, which the body is 

 continually throwing off", and produces a gen- 

 eral feeling of lassitude and discomfort, 

 familiar to everyone. In the dry, light air of 

 mountain regions, a much greater degree of 

 heat may be borne with less discomfort, than 

 is produced by a lower temperature with a 

 higher percentage of humidity. 



Under all circumstances the temperature of 

 the healthy body is about the same, not vary- 

 ing much from 99°. If, from sickness or any 

 cause, the temperature rises a few degrees 

 above this point, death soon occurs, and one 

 of the most important matters in cases of fever 

 is to reduce the bodily temperature ; but, 

 usually, the wonderful vital processes regulate 

 the internal fires very accurately, and the 

 bodily temperature is constant, whether ex- 

 posed to the rigors of an Arctic winter, or to 

 the extreme heat endured by the iron-smelters 

 in their daily toil. 



After a longer or shorter period of hot 

 weather the wind changes, and a current of 

 cool air comes from the far northwest, bring- 

 in<'- comfort and strength once more. These 

 northwesterly breezes are the same which 

 produce the "cold waves" of winter, and 

 their exact origin is uncertain. They are, 

 however, invariably dry and cool, and are 

 always accompanied by fair weather. They 

 are a quite peculiar feature in the American cli- 

 mate, and a most agreeable and delightful one. 



The sea breezes of the coast are a local 

 phenomenon, and are due to the dill'erence in 

 temperature, and consequently the specific 

 gravity, of the air over the land and water. 

 The land absorbs much more heat than the 

 water, and, towards the middle of the day, 

 the overlying air becomes so warm and light 

 that it is forced up by the heavier air over the 

 water, and a steady current of the cooler air 

 flows inland. The waters of the New Eng- 

 land coast, north of Cape Cod, being cooled 

 by a current from the Arctic ocean, produce 

 this phenomenon very frequently. 



The dog-days are an indefinite period of 

 time, when hot, siritry weather is supposed to 

 be especially common. The date is given 

 differently in different almanacs, but usually 

 includes the time from the last of July to 

 the first week in September. In ancient 

 times it was supposed to be governed by 

 the time when Sirius, or the dog-star, arose 

 at the same time as the sun, but the dates are 

 now widely separated, and, in fact, the dog- 

 days have no more real existence than the 

 Indian summer, the equinoctial storm, and 

 many other meteorological superstitions. In 

 many seasons we have found from actual 

 observations a larger number of hot, sultry 

 days in the month of June than in August. 



It is often said that a thunder-storm clears 

 the air, but this is a common error, where 

 cause and effect are confused. Cool, clear 

 weather does not by any means invariably 

 follow a thunder-shower, but, at the end of a 

 period of heat, the current of cooler air which 

 brings a change of weather is also very likely 

 to develop such a disturbance. The clearing 

 of the air, therefore, is not the result, but the 

 cause of the thunder-shower, or, rather, the 

 cool weather and the storm are both due to 

 the same cause — a sudden inrush of cooler 

 air. 



After all, the American summer is certainly 

 a most trying and disagreeable season, but, as 

 it is one of the things that must be endured, 

 the only way is to make existence as easy as 

 possible during its continuance. Over- 

 exertion and exposure to the direct rays 

 of the sun should be avoided as much as 

 possible, and cooling drinks and light, nutri- 

 tious food should take the place of the iieavier 

 viands needed during the more bracing 

 winter season. Ice is an excellent thing, but 

 must be used with judgment ; too much ice- 

 water or frozen food is as bad as a moderate 

 amount is healthful and refreshing. For- 

 tunately, the heated term is a comparatively 

 short one, and the cooler winds of fall and 

 winter come all too soon to those who have 

 made the most of the opportunities for out-of- 

 door life and exercise which the summer has 

 brougiit them. 



Vegetarian Hotel. — A vegetarian hotel is an 

 innovation in London. Tliere are already tliirty 

 vegetarian restaurants in that city. 



WHAT IS A PRACnCAL 

 EDUCATION.? 



The great hue and cry now is for a practi- 

 cal education, which generally means, teach 

 a boy how to do something without teaching 

 the whys and wherefores — without his under- 

 standing the reasons and underlying princi- 

 ples. If we were asked to define a practical 

 education, we should say that it is one that 

 fits a boy to earn his own living. It is gen- 

 erally admitted that a college education, 

 although it may develop the man and bring 

 out his higher capabilities, docs not fit a man 

 to earn money ; therefore, it is not adapted to 

 the masses of people, to whom bread is and 

 must be a primary motive. It is true, a few 

 graduates of colleges succeed in earning a 

 pittance by teaching, and, of these, still fewer 

 rise to the professorial chairs. Another small 

 number drop into editorial work, for which 

 their training has developed any talent they 

 may have already possessed. A college edu- 

 cation is one ol the best precursors for the 

 study of law, medicine, divinity, etc. ; we 

 might almost say an essential prerequisite 

 thereto. But, on the day when a man lca\es 

 his alma mater, proudly bearing aloft his 

 A. B., he is one of the most useless of men, 

 as a rule. 



There are more men who are not intended 

 by nature to be lawyers, doctors, or ministers, 

 and who cannot aflbrd to be literati, or gen- 

 tlemen of elegant Icisiue, than who are in- 

 tended for this small army of reserves. 



Recently we have heard much talk about 

 educating men away from their destiny, and 

 where there is so much smoke there must be 

 some fire. There is a grain of truth in it. 

 Gail Hamilton and Grant XVhite have decried 

 our boasted public school system. Our 

 washer-woman's daughter and our hod- 

 carrier's son attend the common schools, 

 graduate at the high schools, and feel them- 

 selves too good to follow the honest pursuits 

 of their parents, and make some poor effort 

 to live by their wits. When these give out, 

 if they do not fall into crime rather than 

 work, the daughter succeeds in getting an 

 underclerkship in a store, and the son probably 

 gets on the police force, or in the fire depart- 

 ment, or perhaps conductor on a street-car. 

 It is probably true that, with less education, 

 these children of honest laborers would have 

 learned to work, and joined the army of pro- 

 ducers instead of consumers. A Georgia 

 physician, himself a member of the board of 

 education, pointing to a college for colored 

 people, said that it was doing more to injure 

 that race than anything that could be done. 

 When these black girls leave college they are 

 too good to turn cook and chamber-maid, and 

 what are they to do 1 The boys may, a few 

 of them, go to Congress, but the rest won't 

 work now. Well, it is pretty hard to make a 

 negro any lazier than nature created him, but 



