tiny part of the Third World and some of its problems; we had shared the experience of desert travel and its scenic splendour; finally, we had established a bond of self-reliant comradeship in circumstances which, though testing, we now look back upon with an appealing sense of nostalgia. M.P.K.
THE SCHOOL TELESCOPE As part of the 1350 Anniversary celebrations, the School has bought an astronomical telescope. Originally, the School was intending to buy a 5-inch reflector telescope, but the School governors were finally persuaded to buy an 8-inch, Cassegrain-type reflecting telescope made by Celestron in the United States. The telescope is equipped with a tripod, a star diagonal, and several lenses, and cost just over £800. The design of the telescope is as follows:— Light passes through the correcting lens of the telescope on to the main mirror. The size of this parabolic mirror determines the amount of light collected, and also the resolving power of the telescope—the larger the mirror, the smaller the angular separation between stars which can be resolved (i.e. seen as two stars instead of one). The light is reflected from the main mirror to the secondary mirror, which then reflects the light through a hole in the main mirror. An image is produced by these mirrors, and the eyepiece then magnifies the image.
LIGHT BEAM
8 INCH DIAMETER PARABOLIC MIRROR SECONDARY CONVEX MIRROR 59
CORRECTING LENS
