towards each other. This showed that it was the same object seen from different positions, North or South of the ecliptic, and having its locality within the tropics. The Zodiacal light was not seen till the twilight ceased, but that gave only an indefinite idea of the time when it became visible at different places, because in the tropics there was little twilight. In northern latitudes the light had a greater altitude; but owing to the long twilights, was little visible, though it might be observed in the vernal and autumnal equinoxes even in this latitude. The light in the morning was not of the same colour as in the evening; in the first case being greyish, in the other having a reddish hue, depending on the approach or heat of the sun. After sunrise, he had seen it reach the zenith, with a breadth of only 24 degrees. Sometimes the phenomenon was very beautiful, as if a gauze veil were spread over the atmosphere, through which the stars could be readily, though dimly seen. Thus the light stood alone and distinct from all others, its central line being parallel to the ecliptic, a little to the north or south of it, but sometimes corresponding with it. His idea of the origin of the light, from all these facts, was that it was the effect of the illumination of that portion of the earth's atmosphere on which the sun's rays fell in a perpendicular direction. To illustrate this, let it be remembered that if the sun's rays were admitte I perpendicularly through a hole in the shutter, and all reflected light cut off, the atmosphere, or the particles floating in it, become plainly visible as well-defined objects."

On a subsequent day the same subject was brought forward by the Rev. M. Jones, U. S. N., who on the basis of a series of observations made by himself at Quito, maintained the conclusion that the Zodiacal light is a circle of nebulous matter not heliocentric, as heretofore supposed, but geocentric; in short if we understand the view correctly, that this mysterious appearance is an attendant on our planet, related to it as the well known rings are to Saturn. We are not in a position so to investigate the facts presented, as to accept either of these theories as final, but it is evident that Commodore Wilkes and Mr. Jones have collected facts that will bring us nearer to settled conclusions on the subject.

Passing over several papers of a more purely physical character, we reach a singular and elaborate series of papers by Mr. Gibbons, of the U. S. mint, on the

WEIGHTS AND MEASURES OF VARIOUS COUNTRIES.

These papers presented in a condensed form many curious

though well known facts, bearing on Ethnology and Natural History, of which the following may serve as specimens:

"He began by stating that about 1900 years ago, or about 52 years before the Christian Era, Julius Cæsar had described the inhabitants of Great Britain and Gaul, as making use of brass and iron rings by weight for money. Gold ring money of the Celts was also annually dug up in Ireland, and similar money was employed by the Scandinavians, on the shores of the Baltic. They were multiples of one certain ounce or integers of its proportions; the word for ounce being claimed as a purely Celtic one. Recently an ambassador wrote from Antwerp that he had purchased a gold chain of Rubens with the links stamped by the goldsmiths of the day to mark their weight and fineness. In South Africa, at the present day, there was a similar employment of metal rings. And a civilized country of antiquity, as appeared from paintings still remaining on walls, employed rings which were carried for cash to Ethiopia. Another nation had pieces of coin stamped with the likenesses of idols for the same purpose. The old pound of the Anglo-Saxons was called Easterling, from that came the modern sterling. In France there was a pound called the pound of Rochelle, and the Germans named it the pound of Cologne. A new system by which the pound of silver in tale was also made the pound in gross was arranged by Charlemagne, in the eighth century. In England, under William the Conqueror, it was decreed that weights, &c., should remain as they had been under his predecessors. In 1266, by consent of the whole Realm, it was determined that the silver penny, called esterling, should be round, and should be of the weight of 32 grains of wheat taken from the middle of the ear. Twenty of these penny weights were to make an ounce, 12 ounces one pound; 8 lbs. of silver a gallon of wine; and 8 gallons of wine a bushel, the eighth part of a quarter. Troy weight is supposed to have been derived from the Eastern nations, and transmitted first to Troyes, in France, from Cairo, during the crusades. From Troyes it was carried into England by the Goldsmiths, and found favor there under Henry 8th, who began to debase the standard fineness of silver coins, and to reduce their weight. Before this, a statute established a common standard by which silver and wheat were assumed to be the natural tests, the one of the other. Unfortunately, neither was exactly suited for the purpose. It had been found by experiment with white and red wheat from North Ca

rolina North Carolina flour having been reported the finest specimen at the great exhibition in London-that of red wheat 40 to 43 grains were required to balance a grain of silver, and from 28 to 35 or 36 grains of white wheat effected the same thing. In short, grains were not intended to serve as a just measure for perfect comparison, multiplication or division. Again, there was no such thing naturally as pure silver. It was produced only by art, and imperfectly reduced silver could not offer any just rule for the adjustment of weights and coinage. Attempts had been made to ascertain the purity of a silver penny of William the Conqueror, and it turned out there were in it 40-1000 of some base alloy. Now, in the U. S. Mint, at present, 3-1000 of alloy was all that was allowed for casual impurities. It was now never intended to make the metal perfectly pure; but whatever its purity, the rule adopted must be exactly followed out both with respect to the proportion of the precious metal and of the alloy. The old silver penny was a coin, a weight and a measure, and as its character of purity changed, the characters of all moneys, weights, and measures deduced from it were changed in the same proportion, for they did not depend upon the one element of weight or fineness; but on the products of both. The key stone was a penny sterling; but an error in this key stone made the whole arch fall, because the metallurgical inaccuracy was not checked by any metrical exactness. The bases being inaccurate no truth could be elicited from calculations founded upon them."

Troy weight being thus illustrated, the following remarks were made on the carat weights of the East:-"Among Eastern nations carat grains were used to determine the weight of Pearls and precious stones. Originally a bean, the Karat, was thought when dry to vary very little in weight. A natural section divides this bean into halves, which are again cut into quarters and are again divided, the smaller divisions being used to mark the different degrees of fineness of gold and silver The Chinese use a peculiar kind of pea and grains of maize and Indian corn. In Sumatra grains of rice are used. Thus a gardener's trade basket seems to have afforded all the standards required, and all the weights wanted by our ancestors, until nearly the close of the last century. The author then went on to show by the result of various trials the great discrepancy really existing between these original standards of weight, some grains weighing twice as much as others. Hebrew writers say that the barley corn was an

element in the valuation of the shekel. The chemists of the middle ages used nitric acid and muriatic in preparing the precious metals, and in earlier times they had what is called the dry process, which is described by Hebrew writers with great minuteness. In South America the Eastern methods prevail, and it is a remarkable circumstance that a pilot in Pizarro's expedition observed, in one of the native vessels, a scale for weighing gold similar to what he had been accustomed to see in his own country. The principle of procedure in preparing gold has in all ages been the same, although the practice has differed. In the second chapter of the Book of Genesis, the different qualities of gold are spoken of, and through these records of antiquity examples are given, similar to the modern process, of melting, casting, graving and stamping metals. From these facts he concluded that very great progress in the arts and sciences must have been made at the time when these books were written."

Lastly, the avoirdupois weight, according to Mr. Gibbons, can claim a very remote antiquity, and is also based upon the weights of seeds:-"This kind of weight, which he stated to have been fixed in various countries by an arbitrary rule, was anciently called Poids de Mare, and was designed for weighable articles -"Choses Poisibles" and to be used for current market purposes. It had its origin in Babylon, " a city of Merchants," and was carried to Atlantic Spain by colonists from Tyre about 3056 years ago. Spain produced a large amount of gold, and the Royal mint was noted for the purity of its coin, but in the 14th century no less than 150 mints were licensed, so that the coin became so debased that all trade was carried on by barter. At an early period it was said that there was a mint in nearly every county in Great Britain. In ancient times it is supposed that an affinity existed among the weights and monies of the various nations similar to that now existing among modern nations. Thus the average weight of a shekel, a coin of current money, is described as being half an ounce avoirdupois in refined silver, and by Hebrew tradition it weighed 320 common barley corns; and proof of an understood standard of current money in very ancient times is given in the sale of several instances in the sacred writings; as in the sale of Joseph by his brethren; the purchase of a burying ground by Abraham, which was evidently "a cash transaction,” the payment being made in metallic silver, current money among the merchants; and the payment of his fare in a Spanish vessel

by Jonah-all showing that there was a well understood standard, and it is supposed that this standard was computed by the avoirdupois weight. The avoirdupois weight is supposed not to have been introduced into England from Europe until 1335. Mr. Gibbon then went on to speak of the standards of value established at different times in the U. S. and British mints, stating that the coin had a somewhat depreciated value, established by an arbitrary rule adopted for the purpose of convenience, as compared with the original standard in Spain. According to the present value of the ounce avoirdupois, the shekel would be worth 63 cents, or about an English half-crown. He then spoke of the origin of the word dollar, which he derived from the Greek word for image, the word coin being attributed to a similar derivation. This derivation arose from the fact of coins being issued from the temples, the image stamped upon them being a guarantee of the purity and due weight of the coin. Mr. Gibbon then made some remarks upon the relative value of gold and silver, 16 ounces of silver being equal to 1 of gold. He then went on to speak of the certainty, drawn from observations already stated, that a regular coinage must have existed in very early times, and of the fact that some ancient process of mintage must have existed of a simple and inexpensive nature, as it is known that wherever there was a Greek colony there was a Greek coinage. A comparison between the present process and that of the past induces a conviction that the same means were adopted before the days of Moses which were afterwards contrived by Sir Isaac Newton, Master of the British mint during the reign of George the 1st. The following quotation from Deuteronomy, chap. 25, v. 15, is the conclusion of the paper : "Thou shalt have a perfect and a just weight, and a perfect and a just measure shalt thou have, that thy days may be lengthened in the land which the Lord, thy God, giveth thee."

Our old nursery idea that fire will not burn well in sunlight, was overthrown by Prof. Le Conte, in a paper on

SOLAR INFLUENCE ON COMBUSTION.

"He gave a sketch of various experiments tried by other scientific men with regard to this subject. He then explained the experiments by which he had endeavoured to ascertain whether the influence of Solar light on combustion was such as had been indicated by previous experiments, especially those of Dr. McKeever. The result of his experiments was a negative one

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