174 



KNOWLEDGE 



[August 1, 1900. 



religious brotherhoods persists, but the organisation of 

 government is freer and more spontaneous. There is 

 less need to submit so completely to the interfei-euce of 

 the brotherhoods. The chiefs of the families aie apt 

 to set going the machinery of political life by them- 

 selves, ajid they emancipate themselves from the tutor- 

 ship of the religious orders. Thus the authority of 

 purely religious powers tends to diminish while that of 

 the family chiefs increases. Reclus states: — "They 

 respect the maiabouts; at the same time they are 

 suspicious of them, and take care not to let them 

 infringe on the rights of the community. They assign 

 to them special villages situated apart from the tribal 

 villages, and therefore liberty is not likely to be en- 

 dangered." What a change for these men who opened 

 up and organised the desert and who still govern it ! 



Each village forms " a small republic governing 

 itself." All the citizens form part of it; as soon as they 

 carry ai-ms they have the right of voting. The Djemaa 

 meets once a week and decides all questions. One can 

 therefore say that in the desert borders power passes 

 from the religious to the lay form of government; but 

 in its new form this power continues to follow the same 

 tendency that invariably inspires the commuuitary 

 formation, which encroaches upon and in its very nature 

 tends to restrain the initiative of the individual 'n 

 private life. But here the state increases, since, owing 

 to the sedentaiy mode of life, the community of the 

 family is both restricted and enfeebled and opposes a 

 decreasing resistance to the action of an external govern- 

 ment. 



In my next article I propose to deal with other 

 communities having a similar origin from pastoral 

 peoples who have also been constrained to till the soil. 



ASTRONOMY WITHOUT A TELESCOPE. 



By E. Walter Maunder, f.r.a.s. 



VII.— METEORS;— THE PERSEIDS. 



Of all the subjects for study open to the astronomer 

 who has no optical assistance at his command, none can 

 be so easily or so frequently observed, none afford him 

 such an opportunity for really useful work, as do meteors. 

 And though meteors may be observed practically the 

 whole year round, except when cloud or moonlight inter- 

 feres, yet one month ranks pre-eminently as the meteor 

 month — the mouth of August. 



This is due to the occurrence then of the well-known 

 periodic shower of the Perseids ; the " Tears of St. 

 Lawrence." 



It is very striking in looking back into astronomical 

 records to note how very recent is most of our informa- 

 tion concerning meteors. For thousands of years men 

 have been aware that there were " wandering stars to 

 whom was reserved the blackness of darkness for ever." 

 At times, too, they would come, " not single spies but in 

 battalions," in such numbers and with such brightness 

 as to compel attention and create the deepest astonish- 

 ment and fear. But for all those ages it does not seem 

 to have occurred to anyone to try and observe them ; 

 that is to say, to record such facts about them as it 

 was possible to ascertain during the brief moments that 

 they shone. 



There is an immense gulf between the mere admiration 

 of the phenomena of nature and their observation. The 

 first is utterly xunfmitful ; long generations of men pass, 

 each having seen the same kind of event, and yet the 



accumulated experience of ages leads to nothing. But, 

 on the other hand, let one man, or, better, let three or 

 four give a few years to the careful, steady record of 

 everything that they can ascertain about some pheno- 

 menon, however unpromising, and what mai^vellous facta 

 leap into light ! 



How utterly ignorant even recognized authorities were 

 but sixty years ago may be seen from the following 

 quotation from a standard text>book bearing the date 

 1840. 



" The Falling Stars, and other fiery meteors, wliieh are fre- 

 quently seen at a considerable lieight in the atmosphere, and which 

 have received different names according to the variety of their 

 figure and size, arise from the fermentation of the eflluvia of acid 

 and alkaline bodies, which lloat in the atmosphere. When the 

 more subtde parts of the elliuvia are burnt away, the viscous and 

 earthy parts became too heavy for the air to support, and by their 

 gravity fall tn the earth. 



" On the 13th of November, in the year 1833, a shower of meteors 

 fell between Ion. 61° in the Atlantic Ocean, and Ion. 100° in Central 

 Mexico, and from the North American Lakes to the southern side 

 of Jamaica. These fireballs were of enormous size ; one appeared 

 larger than the full moon at rising. They all seemed to emanate 

 from the same point, and were not accompanied by any particular 

 sound It was not found that any substance readied the ground 

 so as to leave a residuum from the meleors." 



It did not seem to occur to the writer of the above 

 description that the circumstance which he mentions— 

 namely, that the meteors " all seemed to emanate from 

 the same point," itself proved that the meteors were 

 entering the atmosphere from outside and were moving 

 along parallel lines at the time of their entry. 



The great display referred to above, however, was 

 the foundation of modern meteoric astronomy. So 

 magnificent a spectacle as was then witnessed not on'y 

 attracted thousands of gazers, it caught the attention 

 of men who were resolved to use every possible ojapor 

 tunity for learning. 



The enormous numbers of meteors seen in the 

 November shower of 1833 rendered it manifest that on 

 that occasion, at any rate, the falling stars seemed to 

 have their origin in a single point of the heavens, and 

 therefore it became an important point whenever a 

 meteor was seen to note exactly the direction of its 

 flight. Humboldt, who had himself seen the great 

 November shower of 1799, writing in 1844, recognized 

 four points in the heavens from which meteors seemed 

 to fall, and drew attention, though with some hesitation, 

 to the reasons for thinking that the November shower 

 was only occasionally to be seen in great force. Sir 

 John Herschel, about the same time, recognised only 

 two showers, those of August (the Perseids) and those 

 of November (the Leonids). Now by the labours of a 

 very few observers, one of whom, Mr. Denning, may be 

 said to have outweighed all others put together in the 

 value and number of his results, we know of many 

 hundreds of radiant points, whilst the researches of 

 Adams and Schiaparelli have enabled us in some cases 

 to trace the meteor streams in their path, not only far 

 beyond the spread of our own atmosphere but to the 

 very limits of the solar system, and they have been 

 shown to be not mere distempers of the air, but bodies 

 of a truly planetai'y nature, travelling round the sun 

 in orbits as defined as that of the earth itself. 



How has this great advance been made? Simply by 

 careful, patient, intelligent, observation. First of all 

 by carefully noting the points in the sky where the 

 meteor was first seen ^nd where it disappeared. This 

 requires a thorough knowledge of the constellations, as 

 indeed all naked eye astronomy does, and great quick- 

 ness of observation. The meteor worker must be able 



