a doubtful struggle for life. This dune does not materially differ from a very large number which cover the banks on the north shore of Loner Island. Their source is the débris of the banks reduced to sand by the action of the waves. The lighter portions of this sand are carried up the slope during fierce winds, and the process is now in operation during every gale. The present forests may delay, but cannot arrest, the final inundation of the land where the sand-hills crown the coast. In Europe the maritime pine and other species of plants whose habitat is the silicious sand have not only arrested the movement of it, but have covered immense areas of waste land with valuable forest. Our native pitch-pine, the Pinus rigida above mentioned, also flourishes on the most sandy soils. There is proof that it formerly grew on portions of the south beach of Long Island, where its foliage was moistened by the spray of the ocean, nor does the occasional overflow of the tides soon destroy it. If these trees are planted abundantly over the surface of these broken hills of sand, their movement would be delayed if not permanently arrested. The sands lie motionless where the force of the wind is broken.
| SKETCH OF SIR CHARLES WHEATSTONE. |
CHARLES WHEATSTONE was born in the city of Gloucester, England, in 1802. In boyhood he attended a private school in his native town, but, while still a lad, he quit school and devoted himself to mechanical pursuits, adopting the trade of a maker of musical instruments. At about the age of twenty-one years he went to London, and there set up in business on his own account. Here the young tradesman evinced a strong liking for scientific research, endeavoring to find out the principles involved in the various forms of musical instruments. He was thus led to the study of acoustics, a branch of science which he cultivated with rare success. His singular mechanical ingenuity enabled him to repeat and extend the experimental results of prior investigators, and the first fruits of his scientific researches were communicated, in 1823, to the Annals of Philosophy in a paper entitled "New Experiments on Sound." Other essays on the phenomena of sound were published by him from time to time; thus, in 1827, he contributed to the Quarterly Journal of Science two papers, the one "Experiments on Audition," the other a "Description of the Kaleidophone." In 1828 he published in the same journal a paper entitled "Resonances of Columns of Air;" in 1831, "Transmission of Sounds through Solid Linear Conductors" (Journal of the Royal Institution); and the same year read at the meeting of the Brit-
