Address J. R. HOLCOMB, Mallet Creek, Ohio. ---------------------------------------------------------------------- EXPLOSIVE DUST. A COMPREHENSIVE description of the Dangers from Dust in various Manufactures and the Cause of many Fires. How combustible substances can explode. Spontaneous Combustion of Iron, Charcoal, and Lampblack in Air. Flour Dust and Brewery Dust Explosions. Explosions of Coal Dust in Mines. Contained in SCIENTIFIC AMERICAN SUPPLEMENT NO. =125.= Price 10 cents. To be had at this office and of all newsdealers. ---------------------------------------------------------------------- =Can I Obtain a Patent?= This is the first inquiry that naturally occurs to every author or discoverer of a new idea or improvement. The quickest and best way to obtain a satisfactory answer, without expense, is to write to us (Munn & Co.), describing the invention, with a small sketch. All we need is to get the _idea_. Do not use pale ink. Be brief. Send stamps for postage. We will immediately answer and inform you whether or not your improvement is probably patentable; and if so, give you the necessary instructions for further procedure. Our long experience enables us to decide quickly. For this advice we make _no charge_. All persons who desire to consult us in regard to obtaining patents are cordially invited to do so. We shall be happy to see them in person at our office, or to advise them by letter. In all cases, they may expect from us a careful consideration of their plans, an honest opinion, and a prompt reply. _What Security Have I_ that my communication to Munn & Co. will be faithfully guarded and remain confidential? _Answer._-You have none except our well-known integrity in this respect, based upon a most extensive practice of thirty years' standing. Our clients are numbered by hundreds of thousands. They are to be found in every town and city in the Union. Please to make inquiry about us. Such a thing as the betrayal of a client's interests, when committed to our professional care, never has occurred, and is not likely to occur. All business and communications intrusted to us are kept _secret and confidential_. Address =MUNN & CO.,= Publishers of the SCIENTIFIC AMERICAN, =37 Park Row New York.= ---------------------------------------------------------------------- =Advertisements.= ---------------------------------------------------------------------- =Inside Page, each insertion - - - 75 cents a line. Back Page, each insertion - - - $1.00 a line.= (About eight words to a line.)