The use of lime in mortar, is to fill up the hollow spaces or vacuities between the grains of sand, and to cement them together, thereby forming a kind of artificial stone. To add any more lime than is sufficient to fill up these spaces, seems to be useless, and to add much more must weaken the mortar; but, if too little lime be used, there will be cavities left between some of the grains of sand, and the mortar will consequently be short or brittle: therefore, when we cannot ascertain the best proportions of lime and sand, it is better to use too much lime than too little.—Ibid.
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Treatment of Gold and Silver Fish.
These beautiful objects of the animal kingdom, though long ago introduced into Europe from China, their native country, seldom breed in such numbers as they might be expected to do. It has been lately discovered that in ponds heated by waste water discharged from steam factories, the gold and silver fish breed abundantly. From this circumstance, it has been suggested, that, as heating hothouses by warm water is now so generally adopted, a portion of this, led occasionally into a garden basin, would keep the water in such a temperament as would not only always be agreeable to the fish, but promote their breeding.—Ibid.
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Climate.
Professor Schow, of Copenhagen, has lately read a paper "On the supposed Changes in the Climate of the different parts of the Earth, during the period of Human History," from which, as far as it has appeared in our language, it seems to be his opinion, that, on a general view, climates are the same now as in ancient times. The identity of the climate of Palestine, now and during antiquity, is thus beautifully made out:—"It will be convenient to begin with Palestine, the Bible being the oldest, or one of the oldest of books; and, although great uncertainty exists about the determination of the plants which are mentioned in it, yet two of them do not admit of any doubt, (and these are sufficient for the determination of the climate of Palestine, in former times,) viz. the date-tree and the vine. The date-tree was frequent, and principally in the southernmost part of the country. Jericho was called Palm-town. The people had palm branches in their hands. Deborah's palm-tree is mentioned between Rama and Bethel. Pliny mentions the palm-tree as being frequent in Judea, and principally about Jericho. Tacitus and Josephus speak likewise of woods of palm-trees, as well as Strabo, Diodorus Siculus, and Theophrastus. Among the Hebrew coins, those with date-trees are by no means rare, and the tree is easily recognised, as it is figured with its fruit. The vine, also, was one of the plants most cultivated in Palestine, and not merely for the grapes, but really for the preparation of wine. The feast of the tabernacle of the Jews was a feast on account of the wine harvest. From a passage where the cultivation of the vine is mentioned, in the Valley of Engeddy, it is evident that the vine not only grew in the northernmost mountainous part of the country, but also in its southern lower part. Besides these, there are other ancient testimonies in favour of the vine. This plant, indeed, sometimes occurs on the same coin with the date palm. The date-tree, in order to bring its fruit to perfection, requires a mean temperature of 78° Fahr. The vine, on the other hand, cannot be cultivated to any extent if the mean temperature be above 72° Fahr. Such, then, must have been the temperature of Palestine, in former ages; and by all that is known of its present climate, the mean temperature seems to be the same now. Nor has the time of harvest undergone any change. Snow and ice, which were known, though rarely, in ancient times, are occasionally met with now and at present, as in former times. The inhabitants make use of artificial heat to warm themselves."—Dr. Brewster's Journal.