waves, and, therefore, the glass is not warmed; but our own bodies, being opaque, do absorb them, thus producing heat, which our sense of feeling makes manifest to us.
The rate of vibration in the ether, as artificially produced in wireless telegraphy, is extremely slow as compared with that of the light waves, ranging from approximately 1,500,000 to 100,000 per second. The wave length, in any such case, is found by dividing the velocity by the rate of vibration; hence for the extreme violet and for the extreme red, 13000 inch, while those employed in wireless telegraphy vary from about 650 feet to nearly two miles.
As is well known, the ether in proximity to the earth is in continual disturbance, which creates the magnetic field surrounding the earth. This manifests its presence in many ways; the most common is its influence on the magnetized needle of a compass, which causes it to point north and south. Wireless waves are propagated through this magnetic field, and follow the curvature of the earth.
When we contemplate the wonders of nature, and gradually fathom her mysteries, that which before seemed impossible now becomes an established fact, and even so wonderful an art as wireless telegraphy loses its magic when we study into the laws which govern it, and see it take its place, with marvels of the past, in the service of man.
