Now it is supposed that, if an inventor, under the existing law, publishes the drawings of an engine which has not actually been constructed, a machine-maker might make the machine, take out a patent for it, and supply the public to the exclusion even of the inventor himself. If the invention is a purely mechanical contrivance, it is quite possible with mere drawings and with the aid of the Mechanical Notation to demonstrate the possibility of its construction and of all its movements, with the same certainty as that with which a proposition in Euclid is proved. It seems then desirable, that some mode of publication should be arranged by which the public should really enjoy the gifts which science may present without risking monopoly by an interloper. $ The subject of co-operation is one of the greatest importance, and like many other social questions neither its principles nor its limits seem to be clearly understood. It is of the utmost importance that the masses should be enlightened on a subject so exciting, and bearing so directly on their interests. But until it has been further investigated, and numerous instances having a practical connexion with its principles have been collected, it is hopeless to attempt a popular treatment of the subject. It would be highly desirable that those of our foreign visitors who have at all studied that most important question, should communicate to us the results of their experience. § The _Mechanical Notation_ to which a slight allusion has been made, is a system of signs by which all machinery may be perfectly described even without the necessity of any explanation in words. It forms in fact an universal language, which will be, when generally employed, capable of being read by every people, just as the Arabic numerals are at present. It has now been in use for more than twenty-five years, during which time many improvements and additions have been made. A considerable portion of it was published in 1826.[13] Amongst the subsequent additions there is one called the Mechanical Alphabet, which consists of very simple but expressive signs placed above those letters of the alphabet used to express certain parts of machinery. Possibly from 100 to 200 of such signs may be required. Now before any publication is made of those already used, it is of the greatest importance that they should be thoroughly revised, and that practical mechanicians familiar with every branch of the art, should contribute information respecting the requirements in their different departments. Those also who are most experienced in the art of mechanical drawing, ought to confer together respecting the new rules according to which all drawings should have letters attached to the various parts of the machinery they represent.