United States or Solomon Islands ? Vote for the TOP Country of the Week !
Acid sulphate fusions, which require comparatively low temperatures, can sometimes be made in platinum, although platinum is slightly attacked by the flux. Porcelain or silica crucibles may be used with acid fluxes. Silica crucibles are less likely to crack on heating than porcelain crucibles on account of their smaller coefficient of expansion.
"These conditions are due solely to the cooling, and persist only while the low temperature lasts." If this increased strength and hardness of a contracted metal are what one would expect on molecular principles, the decreased chemical activity at low temperatures is no less natural-seeming, when one reflects how generally chemical phenomena are facilitated by the application of heat.
The resources of mechanical ingenuity of the time were exhausted in the effort to produce low temperatures on the one hand and high pressures on the other.
There is no doubt we have been rising steadily since leaving the Shambles Camp. The coastal Barrier descends except where glaciers press out. Undulation still but flattening out. Surface soft on top, curiously hard below. Great difference now between night and day temperatures. Quite warm as I write in tent. We are on tracks with half-march cairn ahead; have covered 4 1/2 miles.
A little more or a little less heat makes all the difference between a nebula and a sun, and between a sun and a planet. At one degree of heat the elements are dissociated; at a lower degree they are united. At one point in the scale of temperatures life appears; at another it disappears.
In fact, almost every phenomenon of nature within the range of ordinary temperatures has effects which may be favorable to the crystallization of some substances, and at the same time unfavorable to others; so it will be seen that it is impossible to lay down any rule for it except for named substances, like substances requiring like conditions, to bring its atoms into that state of equilibrium where crystallization can occur.
Mingott issued an imperial summons to him to come and compare diets as soon as his temperature permitted; for old Catherine was now the first to recognise that one could not be too careful about temperatures. Twenty-four hours after Madame Olenska's summons a telegram announced that she would arrive from Washington on the evening of the following day.
But whether or not the adaptation be generally very close, we have evidence, in the case of some few plants, of their becoming, to a certain extent, naturally habituated to different temperatures, or becoming acclimatised: thus the pines and rhododendrons, raised from seed collected by Dr.
Four feet of good soil, providing the underlying strata are not charged with alkali, would give you a good growth of lemon trees if moisture was regularly present in about the right quantity, neither too much nor too little, and the temperature conditions were favorable to the success of this tree, which will not stand as much frost as the orange. Temperatures for Citrus Fruits.
This pure air, and these stones, now so clean, will be crowded with coal, with boxes and barrels, the products of human industry, but let it not matter, for we shall move about rapidly in comfortable coaches to seek in the interior other air, other scenes on other shores, cooler temperatures on the slopes of the mountains.
Word Of The Day