« PreviousContinue »
1.—N0te on the description of the Iron Suspension Bridge near Sagur.
In our account of Major Presgrave’s bridge, vol. II, page 538, there are a few typographical errors, and inaccuracies of expression, which those interested i similar works may desire to see corrected. "9-\
In page 540, in lieu of “ the tension, to be sustained at each point of suspension would be 85.632 tons, including the load," we should have said, following the authority of the printed account of the work, that the “ tension of the bridge and chains unloaded at either point of suspension, is estimated to be 95.632 tons while supposing the clear portion of the platform, 190 feet by 115, or 2,185 square feet, to be crowded with men, at 69 lbs. per superficial foot, the loaded bridge will have a weight of 120 tons ; and the tension on each point of suspension will result, 217.674 tons. This gives 10 tons for the maximum strain that can be applied to the square inch of sectional area of iron. The general tension will of course be less than half that quantity. There are 780 factory maunds of iron in the bridge, which cost in its finished rate about 19% Ca. Sa. Rs. ‘per maund.
2.-—Mr. Precité’s mode of preserving bread for Ships, Bra.
We said nothing of Mr. Previté’s prepared milk, because we did not think that its quality was very agreeable to the palate, in fact we doubt whether it be possible to evaporate milk to dryness without changing its properties; but of Mr. Previté's bread we can speak in the highest strain of encomium, from having made abreakfast off his regenerated rusk of November last, in preference to‘ other fresh loaves and rolls on the table! The mode of preservation adopted is simply to drive oii all the inherent moisture from the bread by a moderate heat, and hermetically seal it in tin boxes until required. It is then exposed to steam, to supply the natural moisture, and rebuked lightly and rapidly on the surface.
Without detracting in any way from the merit of Mr. PREVITE’s invention, we may mention, on the authority of Lieut. Brmnnocx, that the same principle has been long practised at Madras. In the parching land winds in the interior, when bread becomes perfectly dry and hard during a march, the native cooks sprinkle it with water, and place it between. two hot earthen pans over a fire ; the steam penetrates, and softens the whole mass ; the heat is then raised, sufliciently to rebake the surface. VVe do not know if the same simple plan prevails in Hindustan, but the hint is well worth the consideration of travellers in our hot winds by land or river. 3.—Illuetration of Herodotus’ account of the mode of obtaining gold dust in the
deserts of Kobi.
In Hennmv‘s Asiatic nations, vol. 1, we find the following remarks on this subject, commencing with an extract from Herodotus :
“There are other Indians living near the city Caspatyras and the country of Pactyica, (the city and territory of Cabul,) situated to the North of the rest of the Indian nations, resembling the Bactrians, their neighbours, in their manner of life. These are the most warlike of all the Indians, and the people who go to. procure the gold. For in the neighbourhood of this nation is a sandy desert, in which are ants, less in size than dogs but larger than foxes, specimens of which are to be seen at the residence of the king of Persia, having been brought from that country. These creatures make themselves habitations under ground, throwing up the sand like the ants in Greece, which they nearly resemble in appearance. Tne sand, however, consists of gold-dust. To procure this the Indians make incursions into the desert, taking with them three camels, a male one on each
side, and a female in the centre, on which the rider sits, taking care to choose one which has recently foaled. When in this manner they come to the place where tl1e ants are, the Indians fill their sacks with the sand, and ride back as fast as they can, the ants pursuing them, as the Persians say, by the scent ; the female
camel, eager to rejoin her young one, surpassing the others in speed and Per. severance. It is thus, according to the Persians, that the Indians ohtain the
greater part of their gold ; at the same time that the metal is also found, though in less quantities, in mines.”
Herodotus has so accurately marked the situation of these aurifel-0115 deserts that it is impossible to be mistaken. The nation in whose neighbourhood they are situated “live near to Bactria and Pactyica, to the north of the other Indians,” and consequently among the mountains of Little Thibet, or Little Bncharia; and the desert in their vicinity can be no other than that of Cobi, which is bounded by the mountains of the above countries.
There is no doubt that the account of the historian is applicable to this region, We have already remarked that the lofty chain 6f mountains which limit the desert, is rich in veins of gold ; and not only the rivers which flow from it westward, through great Bucharia, but the desert-streams which run to the east and lose themselves in the sand, or in inland seas, all carry down a quantity of gold. sand. Besides, who knows not that the adjacent country of Thibet abounds in gold? Nor can we be surprised if, at the present day, the rivers in question should be less abundant than formerly in that metal, as must always be the case when it is not obtained by the process of mining, but washed down by a stream. As late, however, as the last century, gold-sand was imported from tl.is country by the caravans travelling to Siberia ; and under Peter the Great this gave occasion to abortive attempts to discover those supposed ll Dorados, which were not “ith_ out some beneficial results for the science of geography, though utterly unprofit_
able for the purposes of finance. That these were not ants, but a larger species of animal, having a skin, is
apparent not only from the account of Herodotus, but from that of Megasthenes in A;-rian, (India, OP. p. 179,) who saw their skins, which he describes as being larger than those of foxes. The count Von Veltheim in his Sammlung einiger Auisatze, vol. II, p. 268, etc., has started the ingenious idea that the skins of the foxes, (Canis Corsak, Linn.) found in great abundance in this country, were employed in the washing of gold, and which, as they burrow in the earth, may have given rise to the fable. Bold as this conjecture may appear, it deserves to be remarked, as it is in perfect agreement with what we know of the natural history of the country. The actual observation of fresh travellers can alone afford us a complete solution.” ‘
This idea of the skins of animals being used in the washing of the gold sand elucidates well the marvellous tale of the Grecian author. It is a common practice in Savoy to this day. Perhaps however the simple account published in the first volume of the present journal, page 16, of the mode enhployed by the Burmese in collecting the gold dust of the Kyemluen river by fixing the horns of a peculiar species of wild cow in the small streams coming from the hills, to entangle the gold dust in the velvet or hairy coat with which the young horns are enveloped, may throw some fresh light on the subject. The horns (Mr. Lane was informed, although himself rather incredulous) are sold with the gold dust and sand adhering to them for 12 or 13 ticals a piece. Now may it not be very probable that in the gold streams to the north of Himalaya, whole fleeces of some small animal were employed for the
same purpose, and were occasionally sold entire ?
The instruments for 10 A. M. and 4 P. M. are suspended in the free air of the Laboratory, those for 5 A. M. and 10 1’. M. in the south veranda of a third story
near the cathedral. The register thermometer for extremes is also in the same veranda. A slight shock of an earthquake was felt in Calcutta and to the north-east of Rengal, drc. on the morning of the 31st ult.