Please to inform all the inventors in your town and vicinity, that the Editors of th SCIENTIFIC AMEKICAN have issued an elaborate circular, giving instruction how to secure Letters Patent for new inventions, which they send free to all who may desire a copy. Their great experience for twelve years past in procuring patents enables them to give the best possible advice upon this subject. The 30,000 plates which form the hull of the Great Eastern are bound together by 3,000,000 rivets 1 These bolts hold together the framework of a structure -which wonld carry 10,000 troops to India, wiUi 18,000 tuns of coal and cargo.