steel wire and is partly neutralized by being connected with a second and more delicate needle, made of the smallest species of main spring. This second needle is parallel to the principal one, three eights of an inch above it, and with its poles reversed in the manner of M. Nobili. It is intended to act chiefly as an INDEX and swings above the card. The two needles are firmly connected together by a brass wire. The whole is closed by a glass cover in the manner of a common compass, which it nearly resembles in external appearance. The glass is however pierced in its center by a hole half an inch in diameter, for the insertion of a perpendicular brass tube, four inches high. This tube includes the suspension filament which is fastened to the center of the cap the latter being closed at the top. The projecting wires ascending in an arch, and approaching within a quarter of an inch, terminate, the one in a five cent piece of silver, and the other in a corresponding disc of zinc. Three projecting brass feet, with each a levelling screw, support the instrument. A wine glass of water, applied once to the discs, will deflect the needle from two to five degrees; by repeated applications the needle may be made to vibrate through sixty degrees. When the conjunctive wires of a calorimotor of one and half square feet of zinc, filled with rain water, are laid on the poles of this galvanometer, the needle is deflected to ninety degrees which is the maximum. If it be suffered to remain thus in action, it will retain the needle at about seventy degrees for twenty four hours; how much longer I have not yet determined. The advantages which it seems to me, my instrument possesses are, that the "multiplying" coil being brought the nearest possible to the needle must affect it the most sensibly; being entirely enclosed, it is not disturbed by the agitation of the air; it is compact and elegant in its form. Fig. 1. Is a plan of the ring R, and coil of wire W, half size. Fig. 2. Is a section of the whole instrument. B. The box. R. The ring. W. The wire. N. S. The needle. n. s. The index. D. The dial cut out in the center to show the wires and to permit the needle to be introduced or withdrawn readily, through the opening O. C. The wire connecting the index and needle. G. The glass cover. T. The brass tube including the suspension filament F. Fig. 3. The perspective view, in which the corresponding parts are marked with the same letters as in fig. 2. P. Is an ivory pin by which to raise or lower the needle, by winding up the filament attached to it. Z. S. Is the battery immersed in a wine glass. Cincinnati Female Academy, Dec. 23, 1833. ART. XV.-A Parasite Tree; by GEO. W. LONG, Lieut. 4th. Regt., U. S. Artillery. TO THE EDITOR. Sir.-I have recently, on a visit to Mr. Gee's plantation three miles south of Quincy, Gadsden county, in this territory, observed a natural curiosity, the following description of which may be interesting to you and many of the readers of the American Journal of Arts and Science. It is a yellow pine tree bearing another in a perfectly healthful and flourishing state, like itself and those in the woods around them. The trees, as represented in this sketch, are united about thirty five feet from the ground, where they entwine around each other. The one that is borne, (marked A,) extends down, to within about two feet of the ground, and is alive and healthful to its lowest extremity. These trees have been, in the condition in which they now are, for a period longer back than the first settlement of the country by the present population. They were pointed out by the Indians as a curiosity to the first Americans A who came to Florida. The stump of the tree which is borne, has long since disappeared, and the place which it occupied, is now grown up in small bushes and grass. Tallahasse, Florida, Oct. 26, 1833. It would be desirable, to know the diameter of each of the trees, both near the ground, and at the point where they embrace.-Ed. ART. XVI.-Caricography; by Prof. C. DEWEY. Appendix, continued from Vol. XXV. p. 146. No. 130. Carex Baldwinia, Dewey. No. 37. Muh. Gram. C. fulva? Spicis distinctis; staminifera solitaria cylindracea, bractea trinervi; spicis pistilliferis binis vel ternis tristigmaticis ovatis subrotundis, superioribus sessilibus, supernè saepe staminiferis, infima longo-exsertè pedunculata; fructibus ovatis triquetris subinflatis glabris nervosis longo-rostratis bidentatis, squama ovata acutiuscula subduplo longioribus. Culm 1-2 feet high, leafy at the base, triquetrous, recurved; leaves linear, shorter than the culm, rough on the edge, purple at the base; staminate spike one, with a short three-nerved bract, with oblong obtuse scales; pistillate spikes two or three, upper two sessile, the third long pedunculate and projecting from the sheath, all with leafy bracts, ovate and roundish, densely flowered; stigmas three; fruit ovate, subtriquetrous, subinflated, long-beaked, nerved and two toothed, diverging or reflexed; pistillate scale ovate, obtuse or acutish, nearly half the length of the fruit. Grows in S. Carolina, Georgia and Florida. It is No. 37 of Muh. Gram., and there called C. fulva with a query. It is not the C. fulva of Europe. It is not the C. Elliottii, as it has been thought to be, as both plants can now be compared. It differs from this, in its fruit and scale and general habit; C. Elliottii is a rougher plant, and has inore the habit of C. filiformis, and is rush-like, while this species has the common habit of the Carices. It appears to be between C. folliculata and C. flava. No. 131. C. venusta, Dewey. Spicis distinctis; staminifera solitaria cylindracea; spicis pistilliferis tristigmaticis ternis longo-cylindraceis pedunculatis sublaxifloris, infima longo-pedunculata et exsertè; fructibus ovato-conicis teretibus subtriquetris nervosis scabro-pubescentibus bidentatis, squama ovata obtusa paulo-duplo longioribus. Culm 1-2 feet high, leafy at the base; leaves linear-lanceolate, much shorter than the culm; bracts leafy; staminate spike one, cylindric, an inch or two long, sometimes pistillate in the upper part, and rarely another short staminate spike near the upper pistillate spike; staminate scale oblong, obtuse, tawny on the edge and white on the keel; stigmas three; pistillate spikes three, long and cylindric, loose-flowered, lowest long-pedunculate, sometimes quite sparsely flowered; fruit ovate-conic, subtriquetrous, dark brown, distinctly and many-nerved, scabrous-pubescent, tapering to a two-toothed apex; pistillate scale ovate, short, obtuse, not half the length of the fruit. This beautiful species is found from S. Carolina to Florida. I saw many specimens in the Herbarium collected by Dr. Baldwin, now in the possession of Dr. Schweinitz. It has some resemblance to C. flexuosa, but differs from that species in its fruit and scale and other particulars. It is not a variety of C. flexuosa growing at the south, as the southern plant of this name agrees well with the plant found in the Northern States. ART. XVII.—Internal Improvements of the State of Pennsylvania; No. II. by EDWARD MILLER, Civil Engineer. In the last number of the Journal of Science, I gave a cursory view of the main line between the Delaware and Ohio; and it is my intention in the present to give a similar account of the Branch canals, so far as they are already finished, or far advanced towards completion. Some of these branches will probably be extended immediately, and others at a future day; but my object at present is only to show what Pennsylvania has already accomplished. Her energies and power are daily developing themselves, and it is not probable that she will stop in a career, which binds her citizens together by the strong links of mutual interest, and promises abundant increase to the general prosperity of the commonwealth. The branches are six in number, and take their conventional names from the streams on the banks of which they are generally constructed. These are; the Delaware, Susquehannah, West Branch, North Branch, Beaver, and French Creek. No. 1.-The Delaware division commences at Bristol, on the tide water of the River Delaware, nineteen miles above Philadelphia, crosses Pennsbury manor, the projection formed by the bend of the river at Bordentown, and reaching the western bank near Morrisville, follows it through New Hope and several less important towns, |