the mounting and graduation. By far the finest circles are executed in the workshops of Munich and London.
Not above half a mile from the workshop of Clarke, is the Cambridge Observatory, superintended by Bond the younger. We have already referred to the contributions of Bond the elder to astronomical science. He had the chief merit of inaugurating a new system of observing, which has quite revolutionised practical astronomy. We refer to what is called the American or Electro-recording plan; and our chief object in visiting the Observatory was to examine the details of the plan. America has the undisputed claim to the invention, which, if measured by its result, is one of the most important in modern astronomy. It is questionable, however, whether it should be rated very high, if measured by the inventive genius required. There are certain inventions, which, in the course of things, are inevitable; and it is a mere question of time when the fortunate parties will stumble upon them. For example, the application of electricity to the ringing of bells in large hotels, such as the Hôtel du Louvre in Paris, is a very obvious deduction from former applications, and no one would think it worth while to set up any claim to the invention. No doubt the application of electricity to astronomical observation was not so obvious as this. Still, it was clearly an application that must necessarily have been made in a short time. The
