An account of several new inventions and improvements now necessary for England, in a discourse by way of letter to the Earl of Marlborough, relating to building of our English shipping, planting of oaken timber in the forrests, apportioning of publick taxes, the conservacy of all our royal rivers, in particular that of the Thames, the surveys of the Thames, &c. : Herewith is also published at large The proceedings relating to mill'd-lead-sheathing, and the excellency and cheapness of mill'd-Lead in preference to cast sheet-lead for all other purposes whatsoever. : Also A treatise of naval philosophy, / written by Sir Will. Petty. ; The whole is submitted to the consideration of our English patriots in Parliament assembled.

Dr. Chamberlain's Letter.

Mr. Hale,

WHen I last saw you, you shewed me a Paper addressed by the Plumbers to the Navy-Board, wonderfully decrying your Milld-Lead, commending their own, and be∣cause that amongst several other places, which they ••ay were covered with Mill'd-Lead, that in a short time (being very defective) were taken up, and new laid with Cast-Lead, they mention mine in Essex-Buildings to have been one; you then desired me to give two or three lines in Writing of the truth thereof, which I could not reasonably deny you; and I do here assure you that the same Mill'd-Lead which was first laid on about twelve Years since upon two Platforms at my House there, remains on still very well, free from any such cracks or flaws and ridges they complain of, which I have reason to believe would not have continued so well, if they had been covered with Cast-Lead; for that the Cast-sheets which were laid upon the Cornish next the Street before I came to the House, were afterward in many places so crack'd and cockled, that about eight Years ago, as I remember, the Plumber took it up, or great part of it, and new laid it again: I considered also of the Charge of both wayes, before I made use of the Mill'd-Lead, and was

then satisfied that the whole was cheaper to me, and would prove better than if I had laid it with Cast-Lead of the size the Plumber proposed, and I continue of the same mind still; all which I thought fit to say upon this occasion, and leave it to you to make use thereof as you please, and am

26 Aug. 1690.

SIR,

Your Humble Servant, Hugh Chamberlain.