The Smithsonian Institute has sent to Congress a memorial setting forth that the present Institute building is already too small for the vast amount of articles already placed there on exhibition; that at the late Centennial Exposition the Commissioners of various countries presented their entire collection of exhibits to the United States, which had delegated their care to the Smithsonian Institute, and they had no place for them; that the armory building was being fitted up for the reception of the United States Centennial collection, and they therefore asked that a building be erected for the foreign collection, which could be used as a national museum, or otherwise we should have to offend the donors by keeping their valuable gifts stowed away in cellars and other rubbish receptacles. Mr. Eads, who is now here on the lookout for his pay for his work on the South Pass of the Mississippi's mouth, has received intelligence from the resident engineer at the jetties that the channel through the shoal at the head of the South Pass is now twenty-two feet deep, and that the least width at which twenty feet depth is found is one hundred and ten feet. The principal works to improve this shoal were constructed during the last six months. The low stage and feeble current of the river has delayed their effect until the recent flood from the Ohio reached them, and the problem of deepening the shoal has been fully solved by the rapid scouring away of the obstruction. It is stated that the channel is quite straight and is deepening rapidly. The channel through the jetties at the mouth of the Pass is twenty-one feet deep. The entrance from the sea through the jetties is one thousand feet wide, and through the works at the head of the Pass eight hundred feet. A recent telegram from Nevada states that the Sutro Tunnel (of which I gave you some particulars in one of my letters) has now progressed a total distance of 15,565 feet and has fairly entered the mineral belt, and will soon help to increase the already vast products of the Comstock lode. While on the subject of mining, I will state that the amount of quicksilver produced in California has increased so immensely during the last two years that it has attracted the attention of all interested in the article throughout the world. The receipts for the year have been 63,928 and the exports 48,010 flasks. In addition to the receipts there, probably about six thousand flasks were shipped direct from the mines to Nevada, thus bringing up the total production to over 70,000 flasks, a gain in round numbers of from twelve thousand to fifteen thousand flasks over 1875. The exports in that year were 34,844 flasks, or 13,666 less than in 1876. Occasional. * * * * *