578 



SCIENTIFIC NEWS. 



[June 22, 1888. 



prevails in the present order of things at the time of the 

 vernal and autumnal equinoxes, and will be seen by the 

 explorers who shall hereafter reach either pole and 

 remain there at these seasons. 



The lift above the horizon is due to refraction, which 

 gives to the sun or moon on the horizon an apparent 

 position of 33 min. (rather more than their own diameter), 

 higher than their actual position. In our supposed con- 

 dition of upright axis this refraction would make the 

 day a little more than 4 minutes longer at the equator, 

 and such advantage of day over night would progressively 

 increase with the latitude, until all the country within a 

 circle of about 100 miles diameter around each pole 

 would be a region of everlasting sunshine. Real night 

 would be unknown over a far greater area, owing to 

 the twilight, which would continue until midnight to 

 latitudes about corresponding to that of the town of 

 Hammerfest, in Norway, now so easily reached by 

 holiday excursionists. 



The distinctive polar climate would then be exactly 

 the opposite to that which now prevails. ■ As I showed 

 last week, it is now distinguished by its great extremes of 

 summer heat and winter cold. It would then be — so far 

 as concerns solar radiation — absolutely equal year after 

 year, and through centuries on for ever, with not even 

 the difference of day and night. 



The rest of the world would have no seasons, though 

 subject to the variation of daj' and night temperatures. 

 The behaviour of vegetation would be very remarkable, 

 seed-time and harvest whenever you please. A wheat- 

 field might be divided into 365 or fewer equal parts, and 

 one part reaped every morning, tilled every day, and 

 sown every evening. The same with everything else. 

 By selection of trees and shrubs, daily ripening might be 

 secured. I say 365 or fewer equal parts, because the 

 year as we now understand it would cease to be an 

 epoch. Ever}' daj" being astronomically like ever}' other, 

 each particular plant would have its own particular 

 period. If the interval between the sowing and ripening 

 of wheat were, say, 200 days, then the daily wheat 

 harvest would be secured by 200 instead of 365 sections 

 of the wheat field. 



Fruit trees would probably contract very irregular 

 habits, one branch in bud, another in flower, and the 

 rest in various stages of ripening fruit at the same time, 

 as orange trees partially behave in insular and slightly 

 varying climates now. 



Man would become quite a different creature, not only 

 in his physical habits, iDut morallj' also. He would re- 

 quire no granaries nor stores of any kind of food, would 

 live from hand to mouth, and thus the primary neces- 

 sity for thrift would not exist. At present it takes 

 twelve months to produce a loaf of bread, a leg of 

 mutton, or a sack of wool, and we all have to be fed 

 and clothed in the meantime, are thus all dependent on 

 the savings of somebody ; those who have not saved 

 must sell their labour to those who have, or starve 

 while the produce of their present labour is ripening. 

 Hence originates the distinction between capitalist and 

 labourer. 



The whole social edifice built upon this necessity would 

 fall to pieces by a slight tilt of the earth's axis, and a 

 multitude of other changes which the reader may work 

 out for himself would follow, showing how all the 

 existing proceedings of vegetable, animal, and most 

 especially human, life are dependent on astronomical 

 conditions. 



THE FIRST GEOLOGICAL MAPS. 



OUR countrj'man, Martin Lister, was probably the first 

 to conceive the idea of marking on a map the 

 different kinds of rocks found beneath the surface. York- 

 shire, a county familiar to him from infancy, and one in 

 which there is a regular succession of conspicuously 

 diverse rocks, was the district which he took as an 

 example. In 1683 he proposed to the Royal Society 

 that a " soil or mineral map " should be constructed. 

 "The soil," he says, "might either be coloured by a 

 variety of lines or etchings, but great care must be 

 taken verj' exactly to note on the map where such and 

 such soils are bounded. As for example, in Yorkshire : — 

 I. The Wolds (chalk, flint, etc.) ; 2. Blackmoor {vciooxs, 

 sand-stone, etc. ) ; 3 . Holderness (bog, turf, clay, sand, 

 etc.) ; 4. Western Mountains (moors, sand-stone, coal, 

 iron-stone, lead-ore, sand, clay, etc."). Further on he 

 gives the significant opinion that " such upper soils, if 

 natural, infallibly produce such under minerals, and for 

 the most part in such order." 



Since Lister's map of soils was never actually made, 

 we have to come down a hundred years to the date of the 

 first geological maps which we can discover to have been 

 engraved and published. These bear the title of " Atlas 

 Descriptif et Mineralogique de la France," par MM. Guet- 

 tard et Monnet (folio 1780). Guettard was originally 

 a botanist, and was elected as such to the Academj' of 

 Sciences in 1743. The Duke of Orleans made him 

 Curator of the Natural History Collection in the Palais 

 Royal. Latterly he gave himself up entirely to what he 

 called mineralogy, which had then come to include all 

 kinds of information respecting rocks and soils. Guettard 

 was really what we should now call a geologist. He 

 undertook to map the rocks of France, but finding, in 

 1763, that the task was too great for one man, he per- 

 suaded Lavoisier to share his labours. Lavoisier was 

 then a young man of fortune ; he was chiefly addicted to 

 meteorology, but had already entered upon the chemical 

 researches which were to render his name illustrious. 

 He made many geological excursions to collect materials 

 for Guettard's atlas, not only noting the mineral sub- 

 stances found in different places, but determining heights 

 by the barometer, and analysing all the remarkable 

 mineral waters. The detailed journal of one of Lavoi- 

 sier's journeys, made in 1760, is still extant,* and gives 

 a lively idea of scientific travel in the last centurj'. By 

 1770 sixteen maps had been engraved at the expense 01 

 the Royal treasurj^ The atlas was planned to contain 

 two hundred and thirty, and the whole estimated cost 

 amounted to 85,000 livres (about as many francs), but 

 funds were not to be had to meet so great an expense. 

 It was determined to reduce the atlas to twenty-eight 

 maps, and for these 45,000 livres were required. Of this 

 sum 18,000 were solicited from the King, but the national 

 finances were seriouslj' overburdened and the money could 

 not be found. The maps already engraved fell at length 

 into the hands of Monnet, Inspector-General of Mines, who 

 won cheap credit bj' publishing them as the joint work of 

 Guettard and himself. Lavoisier was not named, and 

 his results were simply stolen by another. Guettard 

 and Lavoisier's maps cannot be called stratigraphical ;. 

 they are rather geographical maps on which a good deal 

 of information about soils, mines and minerals is noted. 

 Measured sections are engraved in the margin. The 

 conception of a regular succession of strata had already 



* See "Revue des Deux Mondes,' December 15th, 1887, p. 837. 



