378 



♦ KNOWLEDGE ♦ 



[Dec. 21, 1883. 



SCIENCE AND SAFETY AT SEA. 

 By Richard A. Proctor. 



IN the Autumn of 1879 the steamship Anzona, 5,000 

 tons, at that time the swiftest ocean-going steamship 

 in existence, was urging her way, at the rate of some 

 fifteen knots an hour, on the homeward course from New 

 York, whence she had sailed but a day or two before. It 

 was night, and there was a light haze, but of danger from 

 collision with a passing ship there was little or none. 

 The captain and crew knew of no special reason for 

 watchfulness, and the passengers were altogether 

 free from anxiety. Indeed, it so chanced that at 

 a time when, in reality, the most imminent danger 

 threatened every soul on board, many of the saloon pas- 

 sengers were engaged in purchasing at auction the niimbers 

 for the next day's run — runs below .350 knots being sold 

 at a very low i-ate indeed. Suddenly a crash was heard, 

 the .ship's swift progress was stopped, and a few minutes 

 later every one knew that the Arizona had run dead upon 

 an enormous iceberg, tlie spires and pinnacles of which 

 could be seen hauging almost over the ship, and 

 gleaming threateningly in the rays of her masthead 

 light. But the risk that threatened her living freight was 

 not that of being crushed by falling ice. The bows of the 

 Arizona were seen to be slowly sinking, and presently 

 there was a well-marked lurch to starboard. The fore 

 compartment and a smaller side compartment were filling. 

 It was an anxious time for all on board. Many an eye 

 was turned towards the boats, and the more experienced 

 thought of the weary miles which separated them from 

 the nearest land, and of the poor chance that a passing 

 ■it-eamer might pick up the Arizonas boats at .''ea. For- 

 tunately, the builders of the Arizona had done their work 

 faithfully and well. Like another ship of the same line 

 which had been exposed to the same risk, save that her 

 speed was less, and, therefore, the danger of the shock 

 diminished, the Arizo7ia, though crippled, was not sunk. 

 She bore np for St. John's, and her passengers were 

 taken on later by another steamer. 



The danger which nearly caused the loss of the Arizona 

 — collision with an iceberg — is one to which steamships, 

 and especially swift steamships, are exposed in exceptional 

 degree. Like this danger, also, it is one which renders the 

 duty of careful watching, especially in the night and in 

 times of haze or fog, a most anxious and iuiportant care. 

 But, unlike the risk from collision with another ship, the 

 risk from collision with icebergs cannot be diminished by 

 any system of side lights or head lights or stern lights, 

 except in just .such degree (unfortunately slight) as a power- 

 ful light at the foremasthead, aided by strong side lights 

 or bow lights, may serve to render the gleam of the trea- 

 cherous ice discernible somewhat further ahead. But to a 

 steamship running at the rate of fourteen or fifteen knots 

 an hour, even in the clearest weather, at night, the dis- 

 tance athwart which which a low-lying iceberg can be seen, 

 even by the best eyes, is but short. She runs over it 

 before there is time for the watch to make their warning 

 heard and for the engineers to stop and reverse their 

 engines. 



But science, besides extending our senses, provides us 

 with senses other than those we possess naturally. The 

 photographic eyes of science see in the thousandth part of a 

 second what our eyes, because in so short a time they can 

 receive no distinct impression at all, are unable to see. 

 They may, on the other hand, rest on some faintly luminous 

 object for hours, seeing more and more each moment, 

 where ours would see no more — perhaps even less — after 

 the first minute than they had seen in the first second. The 



spectroscopic eyes of science can analyse for ua the sub- 

 stance of self-luminous vapours, or of vapours absorbing 

 light, or of liquid.s, and so forth, where the natural eyes 

 have no such power of analysis. Tlie sense of feeling, or 

 rather the sense for heat, which Rrid originally and pro- 

 perly distinguished as a sixth sense (not to be confounded, 

 as our modern classification of the senses incorrectly con- 

 founds it, with the sense of touch), is one which is very 

 limited in its natural range. But .science can give us eyes 

 for heat as keen and as widely ranging as the eyes wliich 

 she gives us for light. It was no idle dream of 

 Edison's, but a thought which one day will be 

 fraught with useful results, that science may hereafter 

 recognise a star by its heat, which the most powerful 

 telescope yet made fails to show by its light. Since that 

 was said the younger Draper (whose loss followed so 

 quickly and so sadly for science on that of his lamented 

 father) has produced photographic plates showing stars 

 which cannot be seen through the telescope by which 

 those photographs were taken. As yet the delicate heat- 

 measurers devised by science have not been applied to 

 astronomical research with any important results. But 

 Edison's and Langley's heat-measurers have been used even 

 in this way, and the very failure which attended the 

 employment of Edison's heat-measurer (the tasimeter, or, 

 literally, the strain measm-er, described shortly before in 

 the Times) during the eclipse of 1878 shows how delicate 

 is the heat-estimating sense of science. When the light 

 of the corona — which has no heat that the ther- 

 mometer, or even that far more delicate heat- 

 measurer, the thermopile, will recognise — fell on the face 

 of the tasimeter the index which Edison supposed likely to 

 move just perceptibly actually flew beyi'ud the index- 

 plate. Thus, though the heat of the corona could not be 

 measured, the extreme delicacy of the tasimeter was demon- 

 strated unmistakably. Langley's heat-nieasurer is scarcely 

 less sensitive, and probably more manageable. But in point 

 of fact each instrument is more sensitive than the heat sense 

 of science is required to be, to do the work [ have now to 

 indicate ; and an instrument can readily be constructed 

 which shall be, in the right degree, less sensitive than they 

 are, though it might be difficult at present to invent any 

 that should be more sensitive. 



The sense of sight is not the only sense affected as an 

 iceberg is approached. There is a sensible lowering of 

 temperature. But to the natural heat sense this cooling is 

 not so obvious or so readily and quickly appreciated that 

 it could be trusted instead of the outlook of the watch. 

 The heat sense of science, however, is so much keener 

 that it could indicate the presence of an iceberg at a 

 distance far beyond that over which the keenest eye 

 could detect an iceberg at night ; perhaps even an isolated 

 iceberg could be detected when far beyond the range of 

 ordinary eyesight in the daytime. Not only so, but 

 an instrument like the thermopile, or the more deli- 

 cate heat^measurers of Edison and Langley, can readily 

 be made to give automatic notice of its sensations 

 (so to speak). As those who have heard Professor Tyndall's 

 lectures any time during the last twenty years know, the 

 index of a [scientific heat-measurer moves freely in re.sponse 

 either to gain or loss of heat, or, as we should ordinarily 

 say, in response either to heat or cold. An index which 

 thus moves can be made, as by closing or breaking electrical 

 contact, or in other ways, to give very efl^ective indication 

 of the neighbourhood of danger. It would be easy to 

 devise half a dozen ways in which a heat indicator (which 

 is of necessity a cold indicator), suitably placed in the bows 

 of a ship, could note, as it were, the presence of an 

 iceberg fully a quarter of a mile away, and speak 



