Philada 12 mo 26th 1812Dear WilliamI should have written sooner if I could have met with an opportunity to send thee the Trigonometry. I now send it by John Lea Jr. who will take it with him to his Fathers at Wilmington, & if he should not visit his brother at E Lewis's will take care to forward it to thee- Francis says the person who left thy letter mentioned it was Simpson's Trigonometry which was wanted, but I hav'nt got that, & perhaps the one which I send will suit thee equally well.With respect to Perpetual Motion I can tell thee, those who were its advocates are somewhat puzzled. [Wormwag] a considerable architect, (the constructor of the new bridge at the [Upper] Ferry on Schuylkill) had obtained leave of Redheffer to make a machine similar to his, & having rec'd from some of the citizens 200 dollars to pay the expense, set about it. He has completed it from what I understand it will not do. Some say it will move for forty minutes & then stop - but all agree in saying his machine is not Perpetual Motion - Now either he has some
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