The attendant shall stop the machine in the middle of its work, whenever he chooses, and as often as he pleases. At each stoppage he shall examine all the figure wheels, and if he can, without breaking the machine, move any of them to other figures, he shall be at liberty to do so. Thus he may from time to time, falsify as many numbers as he pleases. Yet notwithstanding this, the final calculation and all the intermediate steps shall be entirely free from error. I have succeeded in fulfilling this condition by means of a principle in itself very simple. It may add somewhat, though not very much, to the amount of mechanism required; in many parts of the engine the principle has been already carried out. I by no means think such a plan _necessary_, although wherever it can be accomplished without expense it ought to be adopted. CHAPTER XIV. POSITION OF SCIENCE. Science in England is not a profession: its cultivators are scarcely recognised even as a class. Our language itself contains no _single_ term by which their occupation can be expressed. We borrow a foreign word [_Savant_] from another country whose high ambition it is to advance science, and whose deeper policy, in accord with more generous feelings, gives to the intellectual labourer reward and honour, in return for services which crown the nation with imperishable renown, and ultimately enrich the human race. The first question which presents itself to a government desirous of advancing science, is to consider what departments of knowledge it is important that it should reward. This is a point upon which much misunderstanding prevails, and with regard to which interested parties have studiously endeavoured to delude the public. As the fund which can be applied to this purpose even by a generous nation, is moderate, the first limitation of its application ought naturally to be,—to confine it to those discoveries which are from their very nature not immediately capable of becoming a source of profit. One of the most common errors, is to reward persons who have merely acquired an extensive knowledge of various departments of science, but who have neither extended its boundaries by new methods, nor added new principles to its theories.