Another apparatus was constructed, consisting of two vessels, one within the other, having a cover common to both; the inner one to contain _tar_, (as a more convenient substance than rosin;) the outer vessel to contain water, which surrounds the other, and lies under its bottom; or, in other words, a vessel of tar set into a vessel of boiling water. The boiler has a lining of sheet copper, or tin, to promote the ebullition. The tar vessel being riveted to the cover, holes are made through its sides, near to the cover, to allow the steam to pass in, and act on its surface. The cover being secured on, a safety valve is provided for the steam vessel, and two cocks; one over the tar, the other over the water, are fixed contiguously; the first has a tube, or is elongated to reach nearly to the bottom of the tar, which ascends, and is driven out by the pressure of the steam on its surface. Both cocks conduct to a pipe, wherein is placed a large wire, or metallic rod, which about fills the tube, and is perforated obliquely, or zig zag, to increase the length of the passage, and to mingle the tar and steam more intimately. The gases, or vapours, issue from a small orifice at the end of the pipe; and, being ignited by a little fire, into which it is directed, an intense and voluminous blaze is produced, and continues as long as the materials remain unexhausted. A hot brick, instead of the fire, answers the same purpose. This apparatus contained but about one quart of tar, (which must always be nicely strained,) and it lasted one and a half hour, and the flame was sufficient to fill a common fireplace, if not allowed to escape, by its violence, up the chimney. Its force will be according to the elasticity of the steam. I regret being unable, since, to make more exact and varied experiments, to demonstrate the economy of this fuel. This point, however, and the chemical facts, will be the subject of a future communication. And probably a form of a stove may be devised, wherein it may be used for the purposes of warmth, light, and cooking; and another apparatus to light streets. But this invention will be of more special use _as fuel for steam engines applied to navigation_--the purpose principally for which I have purchased the patent right. This may be the subject of another communication. ART. XXII. _On the Changes which have taken place in the Wells of Water situated in Columbia, South-Carolina, since the Earthquakes of 1811-12._ By EDWARD DARRELL SMITH, M. D., _Professor of Chemical and Experimental Philosophy and Mineralogy in the South-Carolina College_. _To Professor Silliman._ DEAR SIR, In answer to your inquiry respecting the changes in our wells, since the memorable period of the earthquakes, I would make the following observations: