862 



THE POPULAR SCIENCE MONTHLY. 



means of escape is given it, and the fire- 

 places furnish that. The course of the air 

 entering the room from the heating appa- 

 ratus is to rise to the ceiling and spread out 

 there. It then descends along the sides of 

 the room exposed to the open air, and is 

 withdrawn by the fireplace if there is any 

 which thus serves to facilitate the distribu- 

 tion of the heat in the lower part of the 

 room. If the opening in the chimney is 

 near the ceiling, the warm air will go out 

 there without descending to the floor. It is 

 important, in providing cold-air inlets for 

 any kind of heating apparatus, to see that 

 they take the air from a point where it is 

 pure. They should also take it from the 

 north or northwest, for the coldest winds 

 come from that direction, and the heating 

 of the house at such times is made much 

 more convenient and safe if the prevailing 

 draughts are made to assist it. If the inlets 

 are on the south side of the house, the fur- 

 nace is liable to be supplied, as is sometimes 

 the case, with air from the northern rooms, 

 entering the house through window-cracks 

 or clown a cold chimney, and sending the 

 heated air out through the cold-air box into 

 the back yard. There are limits, and they 

 are not very wide, to the horizontal heating 

 capacity of the best furnaces. Hence, if 

 the ground-plan of the house is extensive, 

 two or more furnaces should be provided 

 rather than to depend upon one. Steam 

 and hot-water apparatus are better horizon- 

 tal distributors of heat than hot-air fur- 

 naces. As between the two, Mr. Philbrick 

 prefers the hot-water apparatus as more 

 easily managed, and more adjustable to mild 

 temperatures, though its first cost is greater 

 than that of steam apparatus. With either, 

 the main dependence for heat should be 

 upon air that has been heated by passing 

 through the apparatus, rather than by di- 

 rect radiation from pipes or surfaces in the 

 rooms, which should be used only as auxili- 

 aries. 



Long Days and Plant-Growth. The 



Norwegian plant-geographer, Schiibeler, a 

 short time ago called attention to some 

 striking and surprising peculiarities mani- 

 fested by vegetation in high latitudes, which 

 he ascribed to the intensive light-effects of 

 the long days. Most plants in these regions 



produce much larger and heavier seeds than 

 in lower latitudes ; and the difference is in 

 some cases astonishing. Dwarf beans taken 

 from Christiania to Drontheim gained more 

 than sixty per cent in weight ; and thyme 

 from Lyons when planted at Drontheim 

 showed a gain of seventy-one per cent. 

 Grain is heavier in the north than in more 

 southern latitudes ; and Norwegian seed 

 planted at Breslau fell off greatly in the first 

 year. Another remarkable fact is that the 

 increase of weight in northern latitudes 

 takes place through the assimilation of non- 

 nitrogenous substances, while the protein 

 products have no part in it. The leaves also 

 of most plants grow larger in high latitudes, 

 and at the same time take on a deeper, darker 

 color. This peculiarity, first noticed by Grise- 

 bach and Martins, has been observed not 

 only in most of the wild trees and shrubs, 

 but also in fruit-trees, and even in kitchen- 

 garden plants. It has further been observed 

 that the flowers of most plants are larger 

 and more deeply colored, and that many flow- 

 ers which are white in the south become in 

 the far north violet. 



Brain-Work under Pressure. A writer 

 in " The Journal of Science," on " Cram 

 and its Amenities," only utters a truism 

 when he remarks that brain-work is not per 

 se physically injurious, but that, when kept 

 within reasonable bounds and right condi- 

 tions, it appears distinctly favorable to 

 health and long life. He enforces the fact 

 by some happy illustrations. An essential 

 condition to the prosecution of brain-work 

 without injury is that the organ must be suffi- 

 ciently mature before it is subjected to much 

 exertion ; hence, it is disastrous to crowd 

 the brains of children. Another important 

 condition under which study is wholesome 

 " is freedom from anxiety, hurry, and worry. 

 This condition is admirably illustrated in 

 the career of almost all great investigators 

 of nature. Woehler (who died at eighty- 

 two), for instance, contributed no fewer than 

 two hundred and twenty-five memoirs to the 

 scientific journals or to the transactions of 

 learned societies. Almost all of these pa- 

 pers arc of great value, and many of them 

 embody the outcome of months of careful 

 and delicate experimentation. But in no 

 one case was he compelled to finish any of 



