Andrew James wrote: >According to Charles Babbage in his autobiographical "Passages from the >Life of a Philosopher" (I think, or possibly the "Ninth Bridgwater >Treatise" - it's many years since I read it) there is a simple technique >for making a neat hole in a glass sheet using only a centre punch and a >hammer (gently!).
SNIP >I only tried it once, many years ago, and without success! Practice, and >probably best of all a demonstration, might help. Has anyone else heard >of or tried this? I'd *guess* that any punch with a plain point would always cause radiating cracks and shattering of the whole piece BUT a punch that ends in a hollow cone with a sharp edge might have some success. I must experiment with a carpenters' nail punch. Alternatively a flat-ended tool might succeed. Some years ago a craftsman showed me how to cut lapped dovetails in wood with a steel rule which sounds similarly improbable...but it works beautifully. Tony Moss -
