300 



DISCOVERY 



countrymen to acquit Drake of a charge which should 

 never have been brought forward, and to substitute 

 for the vile caricatures of Bernardino de Mendoza 

 the faithful little cameo from Fuller's Worlhies: "A 

 very religious man towards God ; chaste in his life ; 

 just in his dealings ; true of his word ; and merciful 

 to those that were under him " ? 



BIBLIOGRAPHY 

 All the documents available in 1854 for the study of Drake's 

 voyage of circumnavigation were collected in that year by 

 W. S. W. Vaux, F.R.S., for the Hakluyt Society (First Series, 

 vol. xvi). For Oxenham's adventure there is material in the 

 Principal Navigations of Hakluyt (" Everyman's Edition," 

 vii. 64-8 ; viii. 155-6) ; in Purchas His Pilgrims (Maclehose 

 Edition, xvi. 115-16; xvii. 194) ; and in the Observations of 

 Richard Hawkins (Hakluyt Society, vol. Ivii, p. 322). The 

 documents discovered, translated, and annotated by Mrs. 

 Nuttall were published by the Hakluji; Society (Second Series, 

 vol. xxxiv) ; and Grenville's Letters Patent of 1574, edited 

 and elucidated by Mr. R. Pearse Chope, will be found in the 

 Traiisaclions 0/ the Devonshire Association, vol. xlix, pp. 210-46. 



Our Knowledge of the Moon 



By Rev. Hector Macpherson, M.A., 

 F.R.A.S., F.R.S.E. 



The moon is our nearest neighbour in space ; in fact_ 

 it is our earth's peculiar possession — " a detached 

 continent," to quote Flammarion's picturesque phrase. 

 Yet its physical condition is to a certain extent shrouded 

 in mystery ; astronomers are not agreed among 

 themselves as to whether or not changes are taking 

 place on its barren surface. From time to time the 

 pendulum of opinion has swung somewhat violently 

 concerning the physical condition of our satellite. 

 In the early days of telescopic astronomy, extravagant 

 notions were entertained of a lunar world analogous 

 to the terrestrial, with oceans, vegetation, and inhabi- 

 tants. As time went on, it became evident that the 

 moon was a very different world from the earth. In 

 1794 Herschel pointed out " that we perceive no large 

 seas in the moon, that its atmosphere (the existence 

 of which has even been doubted by many) is extremely 

 rare and unfit for the purposes of animal life ; 

 that its climates, its seasons, and the length of its 

 days totally differ from ours ; that without dense 

 clouds (which the moon has not) there can be no rain ; 

 perhaps no rivers, no lakes." Nevertheless, he clung 

 to belief in the habitability of the moon, holding that 

 its inhabitants " are fitted to their conditions as well 

 as we on this globe are to ours." 



Up to the close of the eighteenth century- observa- 

 tions of the moon had been sporadic, and work done 

 had been unsystematic. Consequently, beyond the 

 mapping and naming of the larger surface-features, 

 little progress had been made. The foundation of lunar 

 astronomy — or selenography — as a distinct branch 

 of the science was due to Schroter, of LiUenthal, the 

 contemporary of Herschel, whose long-sustained study 

 marked the commencement of the comparative in- 

 vestigation of the lunar surface. Schroter laboured 

 under the handicap of bad draughtsmanship ; and he 

 lacked that faculty of subordinating theory to obser- 

 vation which was so characteristic a feature of his 

 great contemporary. To him the moon was a living 

 world, with volcanoes in active eruption and an 

 appreciable atmosphere. Madler considered that this 

 preconceived idea impaired the value of his work, 

 inasmuch as he was too desirous of recognising signs 

 of change on the moon. Nevertheless, his observa- 

 tions mark the beginning of that detailed study of 

 the lunar surface which is the necessary prehminary 

 to any tenable theory of the condition of our sateUite. 



Schroter was followed by Lohrmann, a land-surve\'or 

 of Dresden, who turned his attention from the survey 

 of the terrestrial to that of the lunar surface. Lohr- 

 mann had published four out of twenty-five sections 

 of a detailed lunar chart, when failing sight compelled 

 him to abandon the project. About the same time, 

 Madler, then a struggling tutor in Berlin — in co-of)era- 

 tion with his wealthy pupil. Beer — commenced his well- 

 known survey of the moon's surface, with the aid of 

 a four-inch refracting telescope. The result of this 

 survey was the famous chart— issued in four parts, 

 1834-1836 — which was succeeded in 1837 by a descrip- 

 tive volume entitled Der Mond. in which the authors 

 recapitulated the sum of human knowledge concerning 

 our satellite. 



Beer and Madler 's \4ew of the lunar world — change- 

 less, airless, and lifeless — was much nearer the truth 

 than the "baseless fabrics" of Schroter 's visions. 

 At the same time, the publication of the book tended 

 to discourage further investigation. Beer and Madler 

 were believed to have ascertained all that was worth 

 knowing, and to have established the fact that the 

 moon was destitute of change of any kind. 



One or two observers, however, were undismayed 

 by the generally accepted view that the moon was a 

 dead world. Of these the chief was Schmidt, the 

 German director of the Greek National Observatory. 

 Schmidt studied the moon for a much longer period 

 than Madler ; indeed, his great chart, pubhshed in 

 1S78, was the outcome of forty years of untiring labour. 

 In 1866 he brought forward strong evidence of change 

 on the moon's surface, in the almost complete efforce- 

 ment of the small crater, Linn^. Lohrmann and 



