R 



verty 

 ower 



SCIENTIFIC SIDE-LIGHTS 



538 



that he [Bessel] resolved to exchange the 

 desk for the telescope. His reputation with 

 his employers was of the highest; he had 

 thoroughly mastered the details of the busi- 

 ness, which his keen, practical intelligence 

 followed with lively interest; his years of 

 apprenticeship were on the point of expiring, 

 and an immediate and not unwelcome pros- 

 pect of comparative affluence lay before him. 

 The love of science, however, prevailed; he 

 chose poverty and the stars, and went to 

 Lilienthal with a salary of a hundred tha- 

 lers yearly. Looking back over his life's 

 work, Olbers long afterwards declared that 

 the greatest service which he had rendered 

 to astronomy was that of having discerned, 

 directed, and promoted the genius of Bessel. 

 CLEBKE History of Astronomy) pt. i, ch. 

 2, p. 36. (Bl., 1893.) 



2654. POWER ACCOMPANIES COM- 

 PLEXITY Convolutions Few in Idiot's Brain 

 Reversion to Animal Type. Mr. Marshall 

 has recently examined and described the 

 brains of two idiots of European descent. 

 He found the convolutions to be fewer in 

 number, individually less complex, broader 

 and smoother than in the apes. " In this 

 respect," he says, " the idiots' brains are even 

 more simple than that of the gibbon, and 

 approach that of the baboon." The con- 

 dition was the result neither of atrophy nor 

 of mere arrest of growth, but consisted es- 

 sentially in an imperfect evolution of the 

 cerebral hemispheres or their parts, de- 

 pendent on an arrest of development. The 

 proportion of the weight of brain to that 

 of body was extraordinarily diminished. 

 We learn, then, that when man is born with 

 a brain no higher indeed, lower than that 

 of an ape, he may have the convolutions 

 fewer in number, and individually less com- 

 plex, than they are in the brain of a chim- 

 panzee and an orang; the human brain may 

 revert to or fall below that type of develop- 

 ment from which, if the theory of Darwin 

 be true, it has gradually ascended by evolu- 

 tion through the ages. MAUDSLEY Body 

 and Mind, lect. 2, p. 46. (A., 1898.) 



2655. POWER, CONSTRUCTIVE, OF 

 LOWER ORGANISMS Worms Build Tunnels 

 Lined with Cement. The burrows [of earth- 

 worms] run down perpendicularly, or more 

 commonly a little obliquely. . . . The walls 

 of fresh burrows are often dotted with little 

 globular pellets of voided earth, still soft 

 and viscid, and these, as it appears, are 

 spread out on all sides by the worm as it 

 travels up or down its burrow. The lining 

 thus formed becomes very compact and 

 smooth when nearly dry, and closely fits the 

 worm's body. The minute reflexed bristles 

 which project in rows on all sides from 

 the body thus have excellent points of sup- 

 port, and the burrow is rendered well adapt- 

 ed for the rapid movement of the animal. 

 The lining appears also to strengthen the 

 walls, and perhaps saves the worm's body 

 from being scratched. I think so because 



several burrows which passed through a 

 layer of sifted coal-cinders spread over turf 

 to a thickness of iy 2 inch, had been thus 

 lined to an unusual thickness. In this case 

 the worms, judging from the castings, had 

 pushed the cinders away on all sides and 

 had not swallowed any of them. In another 

 place burrows similarly lined passed through 

 a layer of coarse coal-cinders 3% inches in 

 thickness. We thus see that the burrows 

 are not mere excavations, but may rather 

 be compared with tunnels lined with cement. 

 DARWIN Formation of Vegetable Mold, ch. 

 2, p. 32. (Hum., 1887.) 



2656. POWER, ECONOMY OF Auto- 

 matic and Voluntary Actions of the Oyster. 

 Look at the empty valve or shell from 

 which you have just removed its tenant 

 [the oyster]. You notice the oval impression 

 on the inside of the valve showing where 

 the muscle was attached, and you observe 

 on the other and companion valve the neigh- 

 bor impression. Between the two valves of 

 the shell, then, there stretches this strong 

 band of muscular fibers, so strong that it 

 requires the deft hand of the oyster-opener 

 to detach them. This muscle, which closes 

 the valves and keeps them shut, is called the 

 " abductor " ; and while our oyster has but 

 one, the mussels themselves possess two. 

 It is a voluntary muscle this of the oyster, 

 and quite as much at the command of the 

 animal as your own biceps is placed under 

 your behest. 



But the abductor muscle of the oyster is 

 not an organ which is frequently in use. 

 If the shell is closed by its action, how, you 

 inquire, are the valves opened? Look once 

 again at the empty shell. You observe at 

 its beak or apex the remains of a brownish 

 substance. That is the " ligament " of the 

 shell. It is an elastic band, which is put 

 on the stretch when the shell is closed by the 

 abductor muscle. If that muscle relaxes, 

 you see what will happen. The elastic liga- 

 ment will come into play, and by that elas- 

 ticity will keep the shell open. 



Now, as an open shell is the oyster's nat- 

 ural condition, we can note in this contri- 

 vance a saving of power. The shell is kept 

 unclosed by the purely elastic and mechan- 

 ical action of the ligament. The oyster has 

 no need to bother itself over this duty. But 

 it is when the more unusual work of closing 

 the shell has to be accomplished that the 

 vital and muscular act comes into play. 

 Then the muscle acts, and " shuts up shop," 

 so to speak, without delay. Nature is al- 

 ways economical in her distribution of pow- 

 er, and our oyster is kept gaping without 

 the expenditure of any vital activity. WIL- 

 SON Glimpses of Nature, ch. 4, p. 18. (Hum., 

 1892.) 



2657. POWER, ENORMOUS, STORED 

 IN COAL Measured by Comparison with Hu- 

 man Labor. The most important source of 

 mechanical power among those we have men- 

 tioned, and which promises almost to super- 



