5 OCTOBER 1901, Page 14

• THE SPECTRE OF THE BROCKEN.

• [To TH4 EDITOR OP THE "SPECTATOR."] Sra,—In 1884 I wrote to Professor' Tyndall inquiring as ts the nimbus which I had so frequently seen in South Africa. In reply he sent me his monograph, "Note on the White Rainbow," which accounts for the appearance by the occa- sional smallness of falling dew globules' against a dark back- ground, The effect may be produced artificially by a splay Ol sal-ammoniac solution.—I dm, Sir, &c.,