130 



THE POPULAR SCIENCE MONTHLY. 



below. I have seen a master, or more prop- 

 erly * mistress,' thus served several times, 

 each time returning in a dogged sort of 

 resistance to the will of her servitor. 

 These inert mistresses, too, apparently know 

 something of the bitterness of bondage to 

 a capricious domestic help ! " In the course 

 of the migration, one queen was seen to re- 

 sist carriage so vigorously that she was 

 finally dropped, and, refusing to give the 

 slave a hold on the mandibles, was seized 

 by the wing and dragged off. " The luci- 

 dtis ants seemed to have no volition in or 

 direction of this movement. I released a 

 number from their porters during various 

 stages of the transit, and they always wan- 

 dered about with a confused, aimless, and ir- 

 ritated manner until again seized and borne 

 off by slaves." Some of the ants were col- 

 onized in Philadelphia, and observed more 

 closely. The masters were never seen to 

 work. "The colony was changed several 

 times in order to incite to new work in min- 

 ing galleries and rooms ; clusters of lucidus 

 were placed by themselves ; they always re- 

 mained idle. The slaves wrought with the 

 greatest industry and energy as long as 

 there was any need: the masters would 

 crowd into the galleries, and move about in 

 an aimless way, but I never could trace any 

 attempt either at directing or aiding in the 

 work. So, also, I never saw one attempt to 

 eat. . . . Yet they are in good condition, 

 and evidently well fed. They are doubtless 

 fed by the workers, who must disgorge the 

 food." But Dr. McCook could not see this 

 going on. The lucidus ants and the workers 

 both seemed fond of the light, even of the 

 artificial warmth and light of the gas-light 

 globe, where they would *' congregate in the 

 comfortable glow." The association of the 

 two species in their singular relations has 

 resulted in developing the warlike faculties 

 of lucidus at the expense of its disposi- 

 tion to labor ; but has not operated to de- 

 generate the soldierly courage and faculty 

 of Formica Schauffussi^ the working ant, 

 for the individuals of this species will spring 

 to repel a hostile attack as freely and fierce- 

 ly as their masters, and will do it indepen- 

 dently, too ; and they are quite as able as 

 ready to wage sucessful warfare. The luci- 

 dus ant appears to be spread over the whole 

 continent, except perhaps in the far south. 



Improved Electric Motor. A new form 

 of dynamo-machine has recently been de- 

 vised by Mr. C. F. Ileinrich, which the " Tel- 

 egraphic Journal " pronounces an important 

 advance upon previous constructions. The 

 main improvement is in the form of the 

 armature, which the inventor has been led 

 to adopt by a careful study of the Gramme 

 ring and the way in which currents are in- 

 duced in it. He finds that the inner side of 

 the ring (that farthest from the field mag- 

 net) produces on the coil a current opposed 

 to the one induced on the part of the coil 

 immediately in front of the poles of this 

 magnet, and to this extent weakens the cur- 

 rent and causes heat in the coil. When the 

 field magnet is powerful and the ring thin, 

 this effect is reduced, but the inductive ac- 

 tion of the farther side of the ring is not 

 wholly eliminated. He therefore makes the 

 ring channeled, or of horseshoe cross-sec- 

 tion, the coils of wire being wound on the 

 outside only. This removes the metal from 

 the inner portion, and at the same time 

 allows such a free circulation of air around 

 the wires of the coil where they cross the 

 base of the horseshoe that heating is effect- 

 ually prevented. The ring is mounted and 

 revolved between the poles of the field mag- 

 net in the same way as on the Gramme ma- 

 chine. 



Geological Featnres of Behring Strait. 



Some curious geological features are 

 noticed in Mr. W. H. Dall's report of his 

 last summer's work in the coast and geo- 

 detic survey of Alaska and the vicinity of 

 Behring Strait. The country is not wholly 

 without attractions, for when, on the 20th 

 of August, the surveying-vessel, the Yukon, 

 anchored behind Cape Lisburne, on the 

 American shore of the Arctic Ocean, nearly 

 two hundred miles north of Behring Strait, 

 the air was balmy, the sun was warm and 

 bright, no snow or ice was visible, and the 

 banks were covered with flowers, among 

 which daisies, monk's hoed, and forget-me- 

 nots were conspicuous. At Point Belcher, 

 too, the vegetation was quite dense. Beds 

 of good coal, belonging to the true Car- 

 boniferous period, are found at Cape Lis- 

 burne, from which the revenue cutter Cor- 

 win was satisfactorily coaled several times. 

 Large lumps of coal lay on the beach at 



