TRANSIT OF VENUS—AMATEUR OBSERVERS.

Western Star, Issue 52, 7 November 1874, Page 3

TRANSIT OF VENUS—AMATEUR OBSERVERS.

For the information of amateur observers, we quote from the Australasian the following simple method;- of watching the transit of Venus across the sun’s disc as supplied to that paper by Mr Ellery, the well-known Victorian astronomer “ For simply viewing the phenomenon, very simple apparatus will be sufficient. To good eyes protected by deep-coloured or smoked glass, Venus will bo visible after she is well on the sun’s disc. Any ordinary- telescopes, and binocular, opera, or field glasses will give a better view; but, whatever telescope is used, great care is necessary to protect the eye from the intense glare and heat concen-trated-at the- eye aperture, and if proper sunshades are not provide 1 with the telescopes, they must bo improvised before attempting, to look at the sun, for many have lost or injured their eyesight by not attending to this most necessary precaution. Deeply coloured glass especially a piece of red and a piece of deep green or blue together, would be found very safe and pleasant; a piece of blue or green, or doep neutral tint, will also do. nicely. If none of those can be obtained, the old fashioned smoked glass will form an excellent substitute. The proper method of making this is :■ —Obtain two strips of thin, clear glass, say Sin. long by lin. broad (the glass sold for microscopic slides is the best) ; around the margin of one of the surfaces paste a. strip of thick writing paper-about the eighth of an ineb broad, and smoke this surface by holding the slip-over a candle with a long wick or a small kerosene flame (without chimney), taking care to warm the glass gradually at first, or it will crack.. The proper density of the blackening can be got after a few trials. After the right kind of smoked surface has been obtained, the second glass can be . fastened over it; the strips of paper will keep it from coming into.contact; by pasting a strip of thin paper over the.edges to hold this two glasses together a dark shade for observing the sun is formed, which-will last any length of timp.”'