I have waited for some time, since the receipt of your letter, with the samples of the cloth, in hopes a known opportunity might occur for sending you an answer: but am at length forced to write and let the letter take it’s chance.

I think the rendering cloth waterproof, if it does not injure the quality, is a valuable discovery, even tho’ the process should be somewhat costly; because it will inable many to guard themselves against the effects of wet: but it’s importance will be truly great, if the process be so cheap as will admit it to be used for the laboring part of mankind. The rich have so many resources already for taking care of themselves, that an advantage the more, if confined to them, would not excite our interest: but if it can be introduced commonly for labourers, it then becomes valuable indeed. I have tried the samples you were so kind as to send me, and find them sufficiently water proof to answer every desireable purpose. The measures necessary for obtaining a patent are very minutely pointed out by the laws of Congress. They are nearly these. The inventor is to send a petition to the Secretary of state mentioning the nature of his discovery in general terms and praying a patent. He is also to send, what is called a specification of his discovery, that is, a minute description of his process, and a sample of the matter he composes, as well as of the cloth ready prepared, and he pays into the treasury of the US. 30. Dollars. The law requires an oath, the nature of which is pointed out. To this add some small fees (of 3. or 4. Dollars amount at the most) and every thing is done which is requisite for obtaining his patent. I have the honor to be with great esteem Dr. Sir Your most obedt. humble servt