...this distance, and, since the intensity of illumination varies inversely as the area, it varies also inversely as the square of the distance of the screen from the source. Repeat the above, moving the smaller screen to a different distance from the source. Distance...

...futile thus far. It has been determined that the intensity of the fluorescence on the screen varies inversely as the square of the distance of the screen from the Oookes' tube. At first one would l>e inclined to suppose that the X-rays are cathode rays. Roentgen...

...apparatus, and found in the case of three tests, agreeing well with one another, that it varied very nearly inversely as the square of the distance of the screen from the discharge apparatus. Hence the air absorbs a much smaller fraction of the X rays than of the cathode...

...screen is removed from the luminous body. It may be shown, geometrically, that the illumination is inversely as the square of the distance of the screen from the source — that is, that when the distance of an illuminated body from the source of light is doubled,...

...whose lighting powers are as 3 to 4. The intensity of illumination of the screen by either light varies inversely as the square of the distance of the screen from the light. A arid B being 5 feet apart, find the distance, x feet, from A at which the screen is equally...

...observer looks ut the plaster of Paris screen through a small hole at a fixed distance from it, and theu shifts the lamp backwards and forwards till the screen...luminosity of the sky varies inversely as the square of the distance of the screen from the lamp. The colour of the source of light was found troublesome. The...