IMPORTANT TO NAVIGATORS.

South Canterbury Times, Issue 2336, 11 September 1880, Page 2

IMPORTANT TO NAVIGATORS.

The following information will be useful to masters and builders of small vessels : —Captain Thomson, the harbormaster at the Bind;, says—My attention has been called by the masters of many small coasting vessels to errors in their compasses on certain courses, amounting in some cases to as much as two points. These I have invariably found to arise from the proximity of the compass to long iron bolts driven vertically through the deep combings of their half-raised cabins. The hammering in driving and their vertical position, give them strong polarity, in this hemi-

shere, with the red pole upwards, which repels the north or “ rod ” end of the compass needle ; the lower end attracting it. This derangement can in some cases he conveniently compensated, but the surer and better plan is to have the iron bolts replaced by copper or or composition ones, or, it' convenient the compass removed out of their influence. Builders of small vessels of the class referred to should guard against putting iron fastenings near the compass Their being covered with the timber does not prevent them affecting the compasses, as some suppose. Several masters have related to me their narrow escapes through these errors, and I have no doubtsome losses have occurred from the same cause.