572 



THE POPULAR SCIENCE MONTHLY. 



such things for once, without apparent imme- 

 diate damage, but it is with great peril to 

 their future vigor. 



Famons Automatons. — Many ingeniously 

 constructed automatons are mentioned in his- 

 tory or the fiction that goes with it. Among 

 them are a wooden dove that was made b. c. 

 400 ; a fly presented to Charles V which went 

 round in a circle and returned to its starting 

 point ; a bronze fly made by a bishop of Na- 

 ples in the eleventh century which kept real 

 flies out of the city ; an eagle that flew be- 

 fore the Emperor Maximilian; and the brazen 

 men that were made by Roger Bacon, or, ac- 

 cording to others, by Albertus Magnus or 

 Reysolius. A spider of the ordinary size was 

 exhibited in London in 1810, which was 

 caused by wheelwork to walk on a plate, and 

 to shake its paws when taken hold of. A 

 swan was on view about the same time, swim- 

 ming in a basin of water along with some fish. 

 It would seize a fish, swallow it, and then 

 shake its wings. A few years afterward a 

 gold bird appeared, which would come out of 

 a tobacco box, spread its wings, and sing. The 

 famous automaton chess-player was a humbug. 

 It was not moved by machinery, but by a man 

 hidden inside. Some very curious automa- 

 tons were constructed by Vaucanson in the 

 eighteenth century. Among them were a 

 flute-player which played a dozen airs, and 

 another performer which played twenty differ- 

 ent tunes with a tambourine and a flageolet. 

 These " artists " were worked by a strong 

 spring that acted on numerous whistles sup- 

 plied with air from reservoirs which were 

 opened at the proper times. Vaucanson also 

 made an asp for Marmontel's Cleopatra thea- 

 tre, which could coil itself, thrust out its 

 tongue, and hiss. His duck was a very fa- 

 mous imitation ; for it could move its head 

 around in search of food, swallow, and " di- 

 gest." The secret of its " digesting " was 

 discovered by Robert Houdin when he was 

 engaged in repairing it. The food that was 

 given it was removed during the intervals be- 

 tween the exhibitions and suitable " digest- 

 ed" matter, or the imitation of it, supplied. 

 Houdin was very ingenious and was employed 

 to repair other complicated machines. Among 

 them was a mechanical organ that could im- 

 provise variations, that had been taken to 

 pieces without marking where the several 



parts belonged. He succeeded in putting it 

 together again, but it is not known what 

 eventually became of it. The visitors to a 

 certain seminary in the old times were met 

 at the door by an automatic skeleton which 

 welcomed them by clapping its fleshless fin- 

 ger-bones. 



Periodical Variations of Glaciers. — The 



question of the periodicity of changes in the 

 glaciers of the Alps is hereafter to be stud- 

 ied systematically. It has been taken up by 

 the Council of the Canton of Le Valais, 

 which has put the matter in charge of the 

 administration of forests. A report made 

 by M. Forel to the head of the Home De- 

 partment represents that glaciers in general, 

 and particularly those of Le Valais, are sub- 

 ject to variations in shape, which, according 

 to an irregular periodicity, cause them some- 

 times to grow in length, in breadth, and in 

 thickness, and sometimes to decrease, often 

 in very considerable proportions. It has 

 been recognized that most of the great ca- 

 tastrophes which have ravaged the region 

 of the high Alps have been caused by these 

 glacial variations. It is when the glacier ex- 

 tends, lengthens, and arrives at its maxi- 

 mum, that it invades the fields and destroys 

 Alpine chalets, barricades the valleys, arrests 

 the flow of rivers, and creates temporary 

 lakes, the evacuation of which devastates 

 the country ; or else, surpassing its usual di- 

 mensions, it forms an avalanche, the de- 

 structive power of which is terrible. The 

 preparatory study of these variations that 

 has been made in the last few years has 

 shown that their periodicity is much longer 

 than was formerly believed to be the case ; 

 the popular dictum that the increase in size 

 of glaciers recurs every seven years is certain- 

 ly incorrect. Definite figures can not yet be 

 given, but probably the cycle of glacial varia- 

 tion is as much as from thirty-five to fifty 

 years. If 1850 or 1855 be fixed upon as the 

 epoch of maximum, they have been steadily 

 decreasing in past years, so that from 18*70 

 to 1875 not a single glacier was known to be 

 on the increase. Since then an increase ap- 

 pears to have begun in the glaciers of the 

 Mont Blanc group, but most of the others 

 are still retreating or stationary. Hence the 

 phenomenon is one of which a man in an 

 ordinary lifetime can see only a single mam- 



