The objects of mechanical inventions are to furnish the comforts and conveniences ol life, and this object has been accomplished successfully in most ot the departments of mechanism. Inventors have done much, but it is their duty to do more; we are for from having approached that perfection wl ich is atainable; the field for improvement is a great field, it is yet unbounded, and we have m doubt but inventors will yetcbange nearly the whole face of the mechanical world. They are a class of men whose pers-everence and energy are alike notorious; their business is like digging for gold, and their woti like that of the minerssome valuable ira provements being the result of accidental discovery, but a far greater number requiring a great ammount of thought and experiment, before they are brought belore the public Bacon says" Antiquity attributed divine honors to inventors, b'lt conferred only heioic honors upon those who deserve well in civil affiirs, for the benefits of inventions extend to all mankind, but civil benefits only to particular countries; and these civil benefits seldom descend to more than a few ageswhereas inventions are perpetuated through all time." And Dr. Herschel remarks," that an> accession to our knowledge of nature is seen sooner or later, to make itself felt in som* practical application. And a benefit conferred on science by the casual observation or shrewd remark of even an unscientific or illiterate person infallibly repays itself with interest though in a way that might never at first have been contemplated." He should be deemed as great a benefactoi who brings into existence an article or machine which will make us wiser or happier, as he who confers a benefit upon the community in any other way. But inventors owe aduty to themselves, while they benefit the world, for many valuable improvements which have cost them hours of toilsome mental and perhaps physical labor, have been appropriated to public use, and the inventor left without the least remuneration for his services. We believe "the laborer is worthy ol his hire,'; and he is not the less entitled ta it who la bors for the general good in the field ot invention, instead of laboring for individual advantage. Our laws have given to inventors an opportunity ol protecting themselves and ob'aining a remuneration for their services, and they should do it; but to secure their right* they must seek to protect them in seasonas soon as their inventions are complete, or even as soon as valuable ideas are conceived, is the time to claim their protection ; we shall render inventors all the aid in our power in per fecting their inventions by imparting to them the requisite informa'ion, and in protecting them from piracy. The increased circulation of the Scientific American renders more attention to this department of our business indispensable, but notwithstanding this, we are still fully prepared to carefully examine every case that comes under our superintendence The number of examinations of new inventions has also increased so as to require an additional examining force in order to attend promptly to all the numerous cases under oui charge. No case is, however, permitted to leave the office until it has passed the ordeal ol our criticism. This is perhaps one of the principal reasons of our great success in obtaining Letters Patents lor new inventions We sometimes fail, but never for want of tha' care with which business of this kind musi be transacted. This extensive Patent Office business enables us to furnish the readers oi the Scientific American with a great amount of valuable iiifoimation. Our readers are aware that we labor for their interests, and they in turn labor for us A long list of subscribers is Irequently forwarded to us, with the assurance ot approba tion and rmny thanks for the Scientific Ame rican, which weekly finds its way to their homes and firesides, loaded with new improvements, new illustrations, and suggestions, in short, all that is valuable collected from our immense resources, the whole scrutinized,cri ticued, and prepared for practical application. We have every inducement to prosecute our enterprize with energy, to make the Scientific American the repository of science and truth, and a journal of correct intoraation in regard to the mechanical news of the daya publication which dare speak out anri expose humbugs, inconsistencies,and falss theories,ol which the present age is remarkable, as well as remarkable for its great improvements and discoveries.