What inventor, mathematieian, or chemist, has not, while pursuing the solution of an intricate problem, been struck with the vast number of facts strewed all along his path like pebbles upon a seashore. Many of them are new and striking, but in the ardor of the main investigation are too often lost sight of and forgotten. They are gateways to diverging avenues, leading off into new and unexplored regions of thought and knowledge. Would it not be wise to put up some landmarks by which they can be readily referred to when the mind finds itself at liberty to recur to them—some memoranda, in brief, of the facts themselves, and the train of thought suggested by them on first sight 1 We would by no means advocate a discursive habit of thought. The only way to succeed in a mental struggle with an intricate problem is to pursue it singly and unremittingly. But there is no reason why we should, in a search for pearls, reject what may prove a diamond, when we have time,to scan it. With inventors we are sure the habit of recording incidental observations and suggestions made in the working out of their devices, would prove of the utmost value. Many a man working for a thing which he was never able to accomplish, has found what has proved more valuable, than what he directly sought ever could have been. But the majority of such incidental discoveries are never thought of a second time ; or, if thought of, remembered only in a dim, cloudy manner too indefinite to avail in their recovery. It has been said of one of the most successful authors, that he was in the habit of carrying in his pocket a memorandum book, wherein he recorded any idea or peculiar form of expression that struck him as weighty or admirable, on the instant it occurred to him, and that he would even rise from his bed in the night to do this rather than to trust his memory to reproduce it on the ensuing morning. The same has been asserted of some musical composers of note, and we know it to be the case with some literary men of the present time, with whom we are acquainted. We advise, not without having tested its worth, a similar course for inventors and mechanics. Let any one try it for one year, and then carefully examine their notes thus collected, and they will be surprised to find what a mass of interesting and, in many cases, practically useful information a book of fifty or sixty pages, six inches long by toree wide, can be made to hold. Sifting out the chaff there will always remain some good seed, which, sownon jjood ground, will bring forth fruit—some an hundred fold, some sixty fold, some thirty fold. Every mechanic, particularly he who wishes to become a successful inventor, ought to be a student, not only of recorded facts in books, but of facts as they are brought to his notice daily in his practice. But he may not, on the instant a fact presents itself, always stop his work and go into a brown study over it. He may, however, as he leaves his work at noon or at night, put down the data for future study and j thought, and, it of an inquiring mind, he will find the high-' est pleasure and profit in such study. We have little confidence in the ultimate success of those mechanics who are willing to grope blindly along, content to acquire merely that modicum of knowldege which will gain for them a full day's wages. Such men will of necessity remain hewers of wood and drawers of water, while for the more intelligent and better informed workman, there is always an avenue for advance in position and earnings. The following fact will illustrate and enforce the importance of such a course as we advise, better than a column of argument. Prom time immemorial the Government of Great Britain has caused a red worsted thread to be always woven into the cordage manufactured at their roperies. The object of this thread is to prevent pilfering, and to facilitate the recovery of stolen property. One fine morning it struck a poor man in Chatham Yard that a jute thread would do just as well as one of worsted. The experiment was tried. The rope with the jute thread in it was tested in a variety of ways—by being exposed to salt water and the weather for a sufficiently long period—and the result was that worsted was abandoned. Such is the magnitude of government transactions that, by simply substituting that little thread of jute for one of worsted, that country saves 1,800 a year forever,or at least as long as ships want rope. Mr. Baxter nearly doubled the pay of the mechanic to whom the credit of this discovery is due.