We have received a sample of the Breck enridge (Ky.) cannel coal (shale,) with the in junction to examine it, and judge whether it is not equal, if not superior, to the Torbane Hill mineral of Scotland, to which we direct ed attention on page 64, this Vol . SCIENTIFIC AMERICAN, in the following words: "We in vite the attention of our geologists to search for minerals of the same character and quality in our own country." This sample has been sent to us as being a like mineral, and such a

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... ry as the one to which we invited attention. We of course cannot personally testify as to the quality of the seam of this coal, whether it is uniform in quality, or is of great extent Of the sample we have re ceived, however, we have no hesitation in as,erting that it is a very superior cannel coal. It is asserted that it is equal if not superior to the Torbane Hill mineral, which is the richest hydro-carbon mineral in Europe. It must yield a great amount of gas. The TortJane Hill mineral is believed by many to be a rich bituminous shal e; that is the opinion entertained respecting it in Ger m an y by the chemists there. It is transport ed from Scotland to Frankfort for making gas, and found to be cheaper than the old cannel coal. The Breckenridge cannel coal is black er than the Torbane Hill mineral, which is of a brownish color, and somewhat softer. We have before us two reports of this coal, one by John Clowes and F. Headley, and the other by Prof. Benj. Silliman, Jr., Goo. D. Prentice, and Bryan R. Young-acting as com missioners under oath. From the latter re port, we learn that the bed of this cannel coal has been opened at fifteen places; that it underlies at least 4000 acres, and is about three feet thick. "In this thickness," the report states, "we do not include about eight or ten inches of a bituminous shale under the coal, whiche is full of impressions of coal plants, and burns freely." This shale in itself would scarcely be worth working, ow ing to the seam being so thin, but the cannel seam is of very good thickness. The analysis of it makes it inferior to the Torbane Hill min eral, which produces 75 per cent. of volatile matter, but yields no coke; the Breckenridge cannel 63'02 per cent. of volatile matter, but 2'1 of coke, which makes it very excellent for manufacturing gas. 'We do not know wheth er it has been tried by any of our gas works or not; if not, we really think they stand in their own light, in not experimenting with it. ..... -Lunar btlluences. is that of causing earthquakes. M. Alexis Perry, of Paris, asserts that th e moon is the cause of earthquakes, by its varying gravita tion acting on the interior fluid. Thus it is assumed that the interior of the earth is now in a fluid state, and the consequent action of the moon's pressure on the outer thin crust sometimes breaks it, and at other times vio lently agitates the sea of lava within. Vol canoes, it is asserted, are also iubject to this influence. We have but little confidenee in the theory of the moon's producing waves in the interior of the earth. If this were a fact, all partil of the earth would be subject to earthquakes. Now it is well known that this is not the case, but tha t they are local-con fined to certain districts, hence the reasona ble conclusion is, that the cause is local also -perhaps it is magnetic. What effect the moon has upon crops-the time when planted or cut down-we cannot tell, but many of our farmers firmly believe that th.ll times of planting and sowing must be in a�cerdance with the moon's phases. It is also a common belief that timber cut down at full moon is more sub ject to rot, and the attacks of worms, than that cut dming the first and last quarters. There must be some foundation for such general and wide-spread opinions; but their truthfulness we have heard denied over and over again. The ques tion is not yet settled; there is still room for closer observation and investigation. Form of Propellers of Ships. We find a 10llg article in the National In telligencer, of the 20th April, by Thomas Ewbank, Ex Commissioner of Patents, on the above named subject. It is addressed in the for m of a letter to the Secretary of the Navy. When Mr. Ewbank was Commissioner of Pa tents, his first Report was illustrated with figures of different forms of propellers, showing those of the fastest and slowest kinds of birds and fishes; and the best form which he had discovered in making some experi ments. His experiments, he states, developed the fact that the best form for prClpelling vessels, harmonizes with that which nature has provided for the swiftest of flying and swimming creatures. 'For the paddles of steamships, therefore, he recommends that the propelling blades, instead of being thick rectangular pieces of timber, as tbey now are, should be made of some strong thin ma terial, like steel, and should be tapering so as to act with the same area of surface in the depth of the water, that they now have in acting near the surface. To adopt his sug gestions for paddle wheels, these should be made narrower, and the blades of a half dia mond shape, the points projecting and dipping deep in the water. Unless paddles are 80 constructed he believes it is in vain to look for any great increase of speed in steamships. We should really like to see his suggestions carried out. Queries for the Patent Office. Henry M. Paine again before the Public.