25. TO MATTHIAS ARCHIBALD ROBINSON, of Red-Lion Street, Parish of St George the Martyr, county of Middlesex, for "certain improvements in the mode of preparing the vegetable matter commonly called Pearl Barley, and Gritts or Groats, made from the corns of barley and oats, by which material, when so prepared, a superior mucilaginous beverage may be produced in a few minutes." Sealed at Edinburgh 2d Oct. 1823. 26. TO JOHN HENFRY, of Little Henry Street, Waterloo Road, county of Surrey, engineer, and AUGUSTUS APPLEGATH, of Duke Street, Stamford Street, Blackfriars, county of Surrey, printer, for "invention of certain machinery for casting types." Sealed at Edinburgh 17th October 1823. 27. TO WILLIAM ROBSON, of St Dunstan's Hill, Tower' Street, London, printer and stationer, for " a method to prevent or protect against, fraudulent practices upon bankers' checks, bills of exchange, and various species of mercantile, commercial, and other correspondence." Sealed at Edinburgh 17th October 1823. 28. TO JOSEPH JOHNSTON, of Waterloo Bridge Wharf, county of Middlesex, for "certain improvements on drags to be used for carriages." Sealed at Edinburgh 17th October 1823. 29. To JOSHUAH TAYLOR BEALE, of Christian Street, St George's in the East, cabinet-maker, and THOMAS TIMOTHY BENNINGFIELD, of White-Chapel, High Street, county of Middlesex, tobacco manufacturer, for "certain improvements in steam-engines." Sealed at Edinburgh 23d October 1823. 30. TO CHARLES ANTHONY DEANE, of Charles Street, Deptford, in the county of Kent, ship-caulker, for " an apparatus or machine to be worn by persons entering rooms or other places filled with smoke or other vapour, for the purpose of extinguishing fire, or extricating persons or property therein." Sealed at Edinburgh 4th December 1823. 31. TO FRANCIS GYBBON SPILSBURY, of Walsall, county of Stafford, for "certain improvements in tanning." Sealed at Edinburgh 4th December 1823. 32. TO JOSEPH ROGERSON COLLER, of Castle-Magna, near Mallow, in the county of Cork, clerk, for "certain improvements in wind musical instruments." Sealed at Edinburgh 4th December 1823. P. NEILL, Printer. THE EDINBURGH PHILOSOPHICAL JOURNAL. ART. I.-On an apparent Paradoxical Galvanic Experiment. By J. C. OERSTED, Professor of Chemistry and Natural Philosophy in the University of Copenhagen, and F. R. S. E. Communicated by the Author. IN a Memoir, published some months ago, by M. Von Moll, at Utrecht*, this philosopher (already known from various experimental researches) describes an experiment, which, at first sight, appears to indicate a new class of galvanic phenomena. I have submitted this experiment to an attentive examination. Fig. 1. of Plate VII. is the apparatus of M. Von Moll. ABCD is a perpendicular section of a plate of zinc, bent in such a way that its extremities touch, and form a closed circuit. NS is a magnetic needle, properly suspended. The part A of the circuit is plunged in acidulated water. If any point of this circuit under the water be touched by a piece of brass, the motion of the needle indicates an electric current. In order to be certain that the metallic continuity was not interrupted by the interposition of a part of the fluid, I substituted for that in Fig. 1., the circuit ABCDE, Fig. 2., cut out of a plate of zinc. The effect described by the Dutch philosopher was produced by this circuit likewise; but I soon discovered that it was owing to the ordinary galvanic circuits, like that formed by the copper GH, the zinc GA, and the fluid be * Edinburgh Phil. Journal, vol. ix. p. 167. VOL. X. NO. 20. APRIL 1824. P tween H and A, or, as in that in Fig. 3. formed by the copper JK, the zinc KC, and the fluid. The contact of the copper and zinc above the water, or at the surface of the water, produces no effect. In order to make myself sure that a collateral galvanic circuit was capable of producing such an effect on a homogeneous metallic circuit, I made the construction shewn at Fig 4., in which ABCDE is the same homogeneous circuit as before, but JGF is an arch of copper, in contact with the zinc at J, and separated from it at F by a fold hk of paper wetted in acidulated water. In alternately opening and closing this circuit, I found that the needle moved as in the preceding cases. This construction may therefore be considered as composed of a galvanic circuit JGFJ, and a conductor JCDEBAF, which transmits a current similar to that transmitted by JGF. This explanation is confirmed by an experiment made with the construction represented in Fig. 5. in which ZZ is a plate of zinc, CCCC a plate of copper, and AA a vessel of acidulated water. When a magnetic needle is placed at NS, it is deflected according to the known laws; but, if to this circuit there be added the conductor KKK, a part of the electricity passes in it, and acts more feebly on the needle, from being at a greater distance from it. The effect of the second conductor becomes more striking when the needle is placed at n s, and when (after having noted its deviation) the conductor KKK is added; because, in this case, the second conductor being above the needle, tends to give it a contrary deflexion to that given by the first conductor, which is below it. These experiments have the same result when ZZ is made of copper, and CCC of zinc. On applying all this to the constructions in Figs 2. and 3., we observe, that CDEBA is the same thing as the second conductor in Fig. 5. and that the current in the part DE (Figs. 2. and 3.) should have the same direction as in the part CA (to which it is parallel), in the same manner that the currents are similar in CCC and KKK, in Fig. 5. This being granted, we can determine the direction of the current in all the other parts of CDEBA (Figs. 2. and 3.), and experiments with the needle will confirm the predictions of the theory. In some experiments, M. Von Moll substituted a plate of zinc for the copper, with which he touched the zinc circuit, and produced electro-magnetic effects by these means also. This is likewise reducible to a collateral galvanic circuit; for I have proved, by experiments published two years ago, that a galvanic circuit may be made for a short space, by two plates of zinc and a liquid, provided that one of the plates be brought into contact with the liquid before the other. ART. II.-Remarks made during part of a Journey from Christiania to Bergen, in the Summer of 1821. By Professor HANSTEEN *. ON the 22d of June I went from Christiania to Kongsberg, in order to go westward into Telemarken, to visit the celebrated Riukand Fall, and the not less remarkable Gousta Field, which, so far as I know, is the highest mountain in the south of Norway. From that I intended to proceed northward through Nummedal to the borders of Hallingdal, and thence to Eidford in Bergenstift. As geographical measurements had not extended to this part of the country, I expected to find considerable inaccuracies in Pontoppidan's map, and therefore took with me a sextant, chronometer, barometer, and thermometer, to settle, so far as it might be in my power, any geographical points. I was besides interested in making some magnetical observations in the west of Norway: for the western variation of the magnetic needle is greatest towards the west, and its inclination and intensity are greatest towards the north. As experience had taught me that mountains have a certain influence on these three magnetic phenomena, I wished to examine this matter more narrowly in the mountainous district of the west. For this purpose I carried with me a small azimuth compass, an instrument for measuring the declination, and an apparatus with a pendulum for determining the strength of the magnetism of the earth at different places. At Kongsberg, on the 23d of June, we found, by a series of observations, the latitude of the place 59° 40′ 8.8": the chronometer gave the difference of time W. of Christiania 4' 15". The • Translated from the Danish. mean of four observations by the barometer, gave the height of Kongsberg above the level of the sea at 479 Rhenish feet. About Dunserud, which lies a Norwegian mile on this side of Kongsberg, we begin already to enter the mountainous region; but as a good carriage road is kept for the sake of the silver-works all the way to Kongsberg, the inconvenience of mountain travelling is not felt till we are on the west side of that town. For a mile farther on, till you come to Moe, a small carriage may get on with difficulty; but the whole of the rest of the way must be travelled on horseback or on foot, and all baggage must be carried balanced on each side of a horse. To my misfortune I still kept my little car, and as my aged guide, as he has since acknowledged, had not been that way for the last forty years, he mistook the road, and while, to recover it again, he drove along foot-paths, through bushes and underwood, which threatened every moment to upset the car, or at least to tumble out the instruments, in an instant, horse and car sunk deep in a morass, from which he succeeded in getting them drawn out, after four peasants had toiled at the work for an hour and a half with all their strength. 7 After you come to the farm-house of Bolkesiö, you have to ascend a considerable hill, called Bolkeheia, the height of which above the sea we found to be 1763 feet. Here you are suddenly struck with the sight of an imposing range of mountains. Five different mountains, like a row of the scenes of a theatre, shew themselves in the back ground, each more distant and higher and bluer than the others. Farther back Gousta raises his majestic summit, like a sharp-pointed wedge. From this place the road again descends till you come to Tindsiöe, the height of which we found to be 612 feet. 1 My little adventure in the morass between Kongsberg and ว Bolkesiö, had detained me so long, that though, on the 24th of June, I had set out by nine in the morning, I did not reach Bolkesiö till about five in the afternoon, completely exhausted by the burning heat of the sun. At Buewater, at a height of 1471 feet above the level of the sea, the thermometer stood at 18° of Reaumur (721° Fahr.), in the shade, at a quarter after * The Norwegian mile is nearly seven English, about 6%. |