On the contrary the chances are that they will go on increasing till the time arrives, if it ever does, when Mr.Shaw is no longer appreciated.

Mr.Shaw, in fact, if he had written one of his most successful plays at twenty, might, so far as that play is concerned, be idle for ever afterwards, even if he lived to the age of Methuselah, and still be enjoying in royalties the product of his own exertions, though he had not exerted himself productively for some seven or eight hundred years.
There is no question here of whether, under these conditions, a person like Mr.Shaw might not feel himself constrained on some ground or other to surrender his copyright at some period prior to his own demise.

The one point here insisted on is that he could not renounce it on the ground that the wealth protected by it was no longer produced by himself.

If he is entitled to the royalties resulting from the performance of his play at any time, on the ground that every man has a right to the products of his own exertions, his right to the royalties resulting from its ten-thousandth performance is, on this ground, as good as his right to the royalties resulting from the first.

The royalties on a play, in short, show how certain forms of effort, though not all, continue to yield a product for an indefinite period, though the original effort itself may be never again repeated; and herein these royalties are typical of modern interest generally.