Telescope Making

Manawatu Times, Volume 60, Issue 31, 6 February 1935, Page 11

Telescope Making

SOME RECENT ADVANCES American amateur telescope makers after having explored all the fascinating highways of the art, are commencing to invade the byways, for somo of the more advanced workers are now attempting to. evolve an efficient method of automatic guiding for tolescopes used in celestial photography, remarks a writer in Southern. Stars, tho journal of tho New Zealand Astronomical Society. It is a well-known fact, he goes on to say, that the wonderful photographs of the heavens which are so much admired and which, have played such a large part in astronomical progress, are in most eases produced by long exposures in which the astronomer must keep his eye fixed at the eyepiece of a guiding tolescope and adjust tho controls of his instrument so as to keep some certain star on the cross wires. This is necessary in order to compensate for small irregularities in the driving mechanism and to make allowance for the constantly-changing state of the atmosphere which causes the star image to drift slightly in the field. Professional astronomers have found that this work of guiding can only be done effectively by the human eye, but the amateur in his simplicity is stepping in where angels, as it were, would fear to tread. He is fixing magnets around his metal plate holder, and by the aid of photo-electric cell's is attempting to mako the drifting stars themselves guide the plate. Albert Ingalls, in the Scientific American, deplores the fact that American amateur telescope makers are not making any groat contribution to real astronomical work, preferring, as he says, to centre their interest in the mechanical aspect of the hobby. He observes, however, that if the amateurs evolve an entirely automatic guiding system they will have made an exceedingly valuable contribution to astronomy' after all.