TERRESTRIAL MAGNETICS.

Auckland Star, Volume LII, Issue 159, 6 July 1921, Page 7

TERRESTRIAL MAGNETICS.

(To tlie Editor.) Sir. —Kindly allow mc space for a few remarks in reply to Mr. Clement Wragge's letter in your issue of the ISth ult. In my letter of the loth ult. 1 said: —"If a magnetic storm can deflect the needle of the mariner's compass to the extent stated by Mr. Wragge, it is curious that the delicately suspended magnets in our observatories, with (heir ingenious contrivance for magnifying the smallest vibrations whicii take place, fail to record the fact." Mr. Wragge, in a lengthy reply (in whicii he appears to be labouring under the impression that I had stated that magnetic storms could not affect the mariner's compass, nor could they create other disturbances that might do so), advises my studying certain works on magnetism and electricity before again launching out into the public Press. Yet near the end of his letter lie says:— "Magnetometers and niagnetographs in such circumstances may he differently affected in accordance with the trend of the electric isobars, from violent agitation to a more gentle oscillation." This is as good as admitting that they do not record such movements, and Mr, Wragge endeavours to acount for their not doing so. This admission is peculiar after all he had previously said. 1 do not wish to infer that bis reply was not courteous, or that he was trying to get homo on a side Issue, but I might suggest that possibly he got off the mark before he was quite ready.—l am, etc., ALBERT G. ALLOM.