We 'have a number of subscribers whose subscription term will expire with our next number (16.) If all subscribers would send in their subscriptions a week or two before they expire, it would save us from sending notices to them of the same, but many, no doubt, forget their dates and numbers, and it is the attention of such which we wish to arrest.— This volume of the Scientific American, so far, has been distinguished a bo ve the past, and its future numbers, will, we assure all our reader fulfil what we have heretofore said of it, of bemg “ the cheapest and best mechanical paper in the world."