But the most important remark to be made, in this connection, is in reference to the mode of reporting the results adopted by Mr. Kennedy. Instead of giving the amount of metal produced, the number of tuns of ore is stated, and no clue given to the yield of the ore. This is something as an assessor’s report would be, which should give the valuation of the individuals he might be called on to appraise, in pieces of money, leaving it uncertain whether five cent or twenty dollar pieces were intended.
The table given by Mr. Kennedy does not state what amounts of each metal are produced; and, if we attempt to arrive at them by examining the columns of values, it is found to be impossible to decide whether these values are those of the ore as mined before being smelted, or of the metals produced from them. In short, the whole matter is left in such obscurity, that it is much to be wished that the table could be expunged from the Report, as it can only serve to mislead and confuse those who resort to Government documents for information in regard to our metallic and mineral productions.
[1] In point of fact, the amount of bar iron made in the bloomery furnaces direct from the ore is growing less every year, and must be now reduced to a very small figure.
Dr. Cooper remarked that, since the publication of his paper on Californian Mollusca, read before the Academy November 3d, 1862, (see Proceedings, vol. II, p. 202) he finds the generic name Strategus preoccupied, and he now proposes, in its place, the name Navarchus.
Professor Whitney exhibited a magnificent specimen of auriferous quartz, in which the gold was associated with Mispickel, (Arsenical Pyrites.) The weight of the mass was about five pounds, and the value of the gold estimated at $1,500. It was obtained from the celebrated “Fellows Lode,” on the Middle Yuba, in Sierra County. It is stated, on what is believed to be reliable authority, that from $200,000 to $250,000 has been taken from an excavation on the lode only ten feet long and four feet wide, by crushing in hand-mortars. The occurrence of gold in connection with mispickel, in the California mines, seems to be rare, at least in the southern counties. In the specimen presented, the gold formed a coherent, sponge-like mass, when the mispickel was dissolved.
Baron Richthofen remarked, that gold occurs associated with mispickel in Silesia.
Mr. R. L. Harris made some remarks on the comparative friction of car-wheels, on an iron track, when rolling and sliding, as shown by experiments made on the street-railroad in Washington street. Here the greatest grade is five hundred and twenty-eight feet per mile, or one in ten, and it is found that, on a wet day, if the wheels are stopped by the brakes, they will slide on the track; while, if the brakes are not put down so hard but that the wheels can revolve, the car is entirely under control. This is not the popular opinion, and the authorities generally state, that the sliding friction is the greatest; but experience shows, that the friction is really greatest when the sliding and rolling motions are combined.