G. P. J. C, of N. J.—Be pleased to give dates and authorities in making a correction; one man's statement is just as good as another's. We are aware of what is claimed by Dr. Jackson Morton, You are perhaps also aware that their claims ale disputed, Give us the date of Dumas' discovery, c, when you again write. G. W. T., of Mass.- We refer you to the engravings of water wheels, which were published in Vols. 6 and 7 of our paper. The owners of these wheels say, they do as much duty as over-shot or breast wheels; Parker's, VaniXwater's, and Whitelaw Stirratt's, made at Cold Spring, N. Y., are good wheels. The question you ask about the stationary engine, we answer by saying that you cannot make a ten horse engine, into a 20 horse engine, by merely doubling the quantity of fuel. We are in want of sufficient good data ourselves to give you a precise answer. H. D., of N. Y.—We are unable to give you the required information about the ivory black. G. L. P. B., of Me.—Your suggestions in regard to railroad car brakes are believed not to be new. The same plan has been used in this city on omnibuses. It would not be sufficiently effective. Again, companies do not wish to dispense with brakemen, as they are required to assist about the train, throwing wood and baggage; steel is better to face the wooden segment than india rubber. H. M. N., of Me.—There is an English work on the Blowpipe, by Prof. Muspratt, of Liverpool; you will find it fully illustrated and described in the Encyclopedia of Chemistry, published by Henry' C. Baird, Philadelphia, price $5. J. K., of Ohio—We do'not know of any machine for hulling flax. The passing of the flax between fluted rollers is a good method. We have often been spoken to about flax machinery ; it appears to us that some good improvements have yet to be made. L. S. G., of Tenn.—We are not in possession of the definite information you require about the Maryland Charcoal Kilns; we do not know the cost of making the charcoal. We have onlybeen told that the kilns operate well, and we cannot see how it can be otherwise if they are well made. R. M. S., of Ohio—Accept our cordial thanks for your favor of the 20th ult. We appreciate it from an Editorial Brother. J. W., of Ohio—Among the largest pocket-book makers in this city are Washburn, King Co., Geo. B. Cholwell, Levi Chapman, and Bender Fried-lieb. You had better send us one of yours, that we may judge of its novelty. G. D., ofN. ,—We ha,ve heard nothing from your ease sinoe tie aeknowlti4g'!;Q**I*"fr"1**bJir-Bir*—TKZ*X- hope the i;ase Will Come up soon. A. W. L., of Conn.—There is no instance on record of chalk having been found in North America. A. M., of Texas—Pumps for draining mines are generally worked by steam engines, horse or water power can be likewise used, but not with the same effect. B. Y. P., of Me —Yes, a fire-engine from Canada was exhibited at the World's Pair, but was surpassed by one from Prance,—the latter doing as much work with eight men as the Canadian with forty. A. B., of S. C—You ask us what is the most modern description of pump. The newest contrivance is one on the centrifugal principle, and is highly spoken of. L. W. N., of Ga.—No, you cannot take out a patent ; there is nothing new about your invention. A. M. B., of Mass.—Phosphate of lime is found in large quantities in New Jersey. L. S. T., of S. C.—You are quite right, it is a very poor affair altogether. A. II , of Mo.—Crainpton's locomotive is fast becoming the favorite on the English and Prench Bail-roads. B. B. N., of La.—Daguerreotype plates are made in this country, but they are inferior to those imported from Prance. This difference is caused from our want of the requisite machinery for welding the two metals together. A. W. L., of Mass.—Researches into the formation of the Mississippi Delta, c, have been lately undertaken by officers of the U. S. Survey, but the result, we believe, has not yet been published. B. N. W.j of N. J.—The American Society for the Advancement of Science did not meet this year; Cleveland was the appointed place, but the Society were prevented from assembling by the appearance of the cholera in that city. J. T., of Iud— In our last volume we illustrated a great number of boilers and furnaces, and there is Such a near resemblance between yours and some of them, that we do not see on what point we could institute a good patent claim. J. H., of Ohio—It is very difficult to decide in regard to the practical operation of your method of ventilating without a test on a working scale, JWe think the plan not altogether new. J. S , of Cincinnati—Yours of the 28th ult., covering $25, came duly to hand. We shall ship you a lathe as soon as possible. A. L. B., of Ala.—You may use, for your purpose, either Bunsen's or Daniell's Battery. W. P., of N Y.—There was a report published that " strychnine " was used in the operation of making a peculiar ale ia England, called " Allsop's Pale Ale." Liebig was said to have analyzed some and found it S0j but this the celebrated chemist has most strongly denied. I A. B. T., of Miss —Ammonia is much dearer than k it used to be, but why, we cannot say. B. M.s of Ohio—We cannot give an opinion as to the practicability, many things are possible and yet not probable. Money received on account of Patent Office business for the week ending Saturday, Oct. 30:__ W. G. H., of Pa., $47 ; S. W., of HI., $20; D. L. C, of Ct., $30 ; T. S., of Ct, $30 ; K. N , of Pa, $20 . H. B. G., of N. H., $30; C. K., of N. Y. , $30; A. M., of Pa., $20 ; W. P., of Md., $37 ; L. B. P., of N. Y., $30; N. C, of Conn., $25; J. H. B., of N. J., $50 ; A. E. B., of N. Y., $31 ; E. L. G., of N. J., $25. Specifications and drawings belonging to parties with the following initials have been forwarded to the Patent Office during the week ending Saturday, Oct. 30: S W., of 111 ; E. L. G., of N. J.; A. T., of N. Y. ; J. T., of N. Y.; J. E., of N. Y.; K. N., of Pa. ; A. M., of Pa ; P. B., of N. Y. ; A. E. B., of N. Y.; N. C, of Ct.; J. H. B., of N. J. ; E. Van C, of Pa.
This article was originally published with the title "To Correspondents"