inches used to be considered a largo size for the mirror of an astronomical telescope. His first great telescope had a twelve-foot mirror. There is a most exciting account in Mrs. Herschel's Life of Caroline Herschel, of the failure of the first casting of the mirror for the thirty-foot reflector. The molten metal leaked from the vessel containing it and fell on the stone floor, pieces of which flew about in all directions as high as the ceiling. The operators fortunately escaped without serious injury. "My poor brother fell, exhausted with heat and exertion, on a heap of brickbats." The disappointment must have been intense, but nothing ever baffled these indefatigable workers, and the second casting was a complete success.
Five years after she had joined her brother at Bath, Caroline made her first appearance as a public singer. She was very successful, and her friends anticipated that her well-cultivated and beautiful voice would become a means of providing her with an ample income. She, however, had so fully identified herself with her brother's astronomical labours, that she only regarded her musical acquirements as a means of setting him free to devote himself more completely to the real object of his life. His fame as a maker of telescopes had by this time spread all over Europe, and many scientific societies, royal persons, and other celebrities, ordered telescopes of him. On these orders he was able to realise a large profit, but Caroline always grudged the time devoted to their execution. Her aim for her brother was not that he should become rich or even well-to-do, but that he should devote himself unreservedly to advance the progress of astronomical science. She was ready to live on a crust, and to give herself up to the most pinching economies and even privations, for this end. She was the keeper of her brother's purse, and received his commands to spend therefrom anything that was necessary for herself; her thrift and self-denial may be judged from the fact that the sum thus abstracted for her own personal wants seldom amounted to more than £7 or £8 a year.
