A DANGER DETECTOR.

Otago Daily Times, Issue 8112, 22 February 1888, Page 6 (Supplement)

A DANGER DETECTOR.

We have had the pleasure of inspecting a very simple) instrument invented by Captain W. R. Chatfieki, of tho Union Steam Ship Company's steamer Wairarapa, which is intended to take bearings of objects and points of danger and to ascertain the distance a ship will pass off such points Home time before she reaches the vicinity. The instrument, which is made of solid brass, was. constructed iv accordance witd Captain Chatfield's designs by Mr D. M'Murrick, the chief engineer of the Wairarapa, and that gentleman is deserving of very great credit for the very real mid perfect manner in which he has turned out the work. It is intended to fix the instrument,, which bears the motto " Caveuilo Tutus," into a. teak bed, and this being portable, can be shifted to either side of the bridge deck at pleasure. Toe superiority of this invention to us is very apparent, and it is immensely preferable to tho old system of the " four-point beniiug," and no doubt will shortly supersede that system both. In her Majesty's nhips and those of the mercantile marine—more particularly, wo hope, on our own coast?, which are very far from being perfectly surveyed, many points both of the North and South Islands which are extremely dangerous being very imperfectly deiined on the chart at preseut in use. The merits, of this little instrument are shortly these:— First, tho position of the ship is enabled to. be ascertained (when approaching a point of. danger) much earlier than undtr the present, sysrem, while the object and its adjacent dangers, arc; fully from 5 to 5i points before the bean',, when a bearing is taken by it— i.e., that the. observer can ascertain within a distance of £■ tenth of a mile, or less, at what distance tho ship will pass off the danger fully from 10 to 15 miles before reaching it. Now, in using tho old four-point bearing the ship must be brought abreast of the danger before the observer can possibly determine its position. Again, the proees.< of taking a four-point bearing occupies much more time than that of the present invention and continues much later, cooing behind to an extent equal to about two-thirds or the time occupied by the present discovery. This saving of time in ascertaining the position of a ship is of vital importanuc in these days of high-class ships of great speed, and we have not tho slightest doubt Captain Chatfield's invention will be gladly recognised by all shipmasters. Ie is only f slr to mention that; Mr M'Murrick has turned Gut tho model in a manner quite, equal to that of any rr.titheinai.ical instrument maker, which shows that he has worked con amore with his commander to make the new invention a success. Wo hear that Captain Chntfleld has already patented the instrument.