Copy letter from Herbert Rix, to Henry Wilde, Fellow of the Royal Society 'Dear Mr Wilde, I am very sorry to learn from you the mistake which has crept in. It appears to be purely a printer's mistake. In correcting 32" to 32', the 3 in 23 seems to have dropped out, and they have accidently substituted a "0". The number is to be published to-day, and I am afraid that I am too late to get an erratum slip in, though I am trying to do so. If I do not succeed I shall put an erratum slip in the following number, which will be bound up with the whole volume. I am, yours truly, H Rix Asst. Sec. R.S. [Assistant Secretary, Royal Society]'. 25 May 1894