The Bombay Scout Gazette. The Journal of the Bombay Provincial Boy Scout Council February 1925

0.0jecr Unfortunately the whole of the light which passes into the lens cannot be utilised for the making of the image but the better the lens and the more light it passes for this purpose. [...] The former is the more common and the values given to each stop represent the diameter of that stop divided into the focal length of the lens that is the distance between the lens and the film or plate when it is set at infinity. [...] If the stream is muddy at bottom leave the ledger rather low on the legs so that it can rest on the mud but if the bottom is rocky keep it up a couple of feet or more so that it does pot rest on some rock and make the trestle rocky." Lay out the legs with butts to the bank and mark with a chalk ring the places for the ledger and transom. [...] We will have to leave the completion of our trestle till the next issue but remember what I said about where the square lashing had to be commenced in the first article—elove hitch on the inside on the leg that is under the transom and above the ledger. [...] The combined item of the Zulus and the Fire Brigade was the best on the programme.