The only experiments on the resistance to torsion of woods that I have been able to find are those of Benjamin Bevan, in the “ Philosophical Transactions ” of 1829, p. 127. As these may interest the members of the Aeronautical Society I give below a list of his results. I have, however, taken the liberty of substituting my own records for the average weights per cubic foot, as Bevan gives but few, and these to my mind are unsatisfactory, being the result of single trials, whereas mine are the mean of series of tests collected from all sources. I have then rearranged the list according to these weights in order to test Bevan's suggestion, that “the modulus of torsion bears a near relation to the weight of the wood.” Certainly the higher results are found amongst the heavier woods; there are, however, a few exceptions that render a blind confidence in this rule somewhat dangerous and it should be accepted as a rough guide only. I regard it more as a demonstration of the very general fact that, apart from freaks of structure, heavy woods are in all respects stronger than light woods.