February 5, 1886.] 



SCIENCE. 



131 



spongy masses, at other times as long, firm, ivory 

 processes of the most varied shapes, several inches 

 or more in length. The disease is more or less 

 hereditary, nevertheless its apparent frequency 

 among the ancient Incas is interesting. 



Of more especial interest, however, is the re- 

 lation which Virchow surmises to exist between 

 this multiple exostosis and the bony growths 

 found with remarkable frequency in the ear- 

 canals of the ancient Peruvian crania. Nearly 

 two scores of specimens have been described, 

 in which either one or both auditory canals were 

 more or less filled with bony growths, usually 

 near the middle. As hi nearly all these cases the 

 peculiar flattening or elongation of the occipital 

 region occurs to a greater or less extent, some 

 have assigned this as the cause. Others have 

 thought that the custom, so common among the 

 Incas and other non-civilized races, of wearing 

 rings or large disks of metal in the fleshy ear, had 

 produced the affection. To both of these views Vir- 

 chow objects. Not only have cases been observed 

 among the North American Indians where there 

 i$ no cranial deformation, but in the Incas them- 

 selves deformed skulls without, and undeformed 

 skulls with, the exostosis, are known. The very 

 common custom among many races of the present 

 day, of wearing foreign substances in the ears, is 

 not known to produce this result. The author 

 believes them to be due to abnormal ossification, 

 of a nature either closely related to, or identical 

 with, that in other parts of the skeleton. Why 

 this disease should have occurred with such 

 greater frequency among this race we do not 

 know, and we can only speculate upon the extent 

 that it affected the audition. The effects of the 

 disease must have been produced in childhood, 

 probably earl} . In many cases the auditory canal 

 is entirely closed on one or both sides, in others 

 much narrowed. That it must have diminished 

 the power of hearing, is evident. To what extent 

 absolute deafness was caused, one cannot say. 



LARGE VERSUS SMALL TELESCOPES. 



The critical observer can hardly fail to have 

 noticed, during the past few years, the setting-in 

 of a slight reaction against the monster telescopes 

 and their capacity for advanced astronomical 

 work. Perhaps this is not better defined at present 

 than a tendency to reaction merely ; and it seems 

 to have had its origin mainly with a few pos- 

 sessors of medium-sized instruments, who, per- 

 haps, had failed in their efforts to procure larger 

 ones. Any astronomer who has had experience 

 in the adaptation of different kinds of observa- 

 tional work to the varying capacity of different 



instruments knows very well that there is work 

 enough of a sort which the largest telescopes only 

 are fitted to perform in the best maimer ; and he 

 also recognizes the fact that in other times of re- 

 search, which are happily by no means exhausted, 

 the small telescopes have many advantages over 

 the large ones. But these relate rather to the 

 mechanical than to the optical parts of the tele- 

 scope. 



It is not too much to say that the methods pecul- 

 iar to the opticians of the present day have ad- 

 vanced the construction of the telescope to a degree 

 of perfection which far surpasses the apparent 

 possibilities of observational astronomy in other 

 directions. If the optician gives the astronomer a 

 practically perfect instrument, and the latter finds 

 its performance disappointing, one or other of 

 three things will be true : either he has set it 

 up in a bad atmosphere, or the work to which 

 he has put the instrument is ill adapted to its 

 size, or (it is a good thing for every ambitious 

 fledgling to institute this modest though often 

 disastrous inquiry) the trouble resides in the cere- 

 bro-optical apparatus just outside the eye-piece. 

 The first of these conditions appears in a fair way 

 to be partially removed in the early future by the 

 building of mountain observatories in regions 

 where great steadiness of the upper atmosphere is 

 insured ; the second gradually removes itself with 

 every new experience ; while the third constitutes 

 a very serious obstacle to the progress of the 

 sciences ; for what can the conscientious astronomer 

 do with the work of a bad observer ? He hesitates 

 to mingle bad observations with good ones, for he 

 cannot tell how much the accuracy of the final 

 result may be impaired ; nor does he like to reject 

 the bad ones, because his work is then open to the 

 charge of incompleteness ; and, besides, the bad 

 observer makes it an invariable rule to omit all 

 data which might help the theoretical astronomer 

 to find out just how bad his observations are. 



Until lately, those who have been discussing in 

 astronomical journals the relative merits of large 

 and of small telescopes have quite overlooked the 

 astonishing variation in the eye-power of different 

 observers. As a general rule, — and for a very 

 obvious reason, — the large telescopes come into 

 the possession of the best observers, while the 

 weaker eyes and heads must continue their use of 

 the smaller instruments. Notwithstanding this 

 natural result of evolution, the lesser telescope 

 sometimes seems to have the greater advantage. 

 While fully realizing the superior power of the 

 great telescope, the observer using it has learned 

 to be very cautious in pronouncing upon what he 

 sees : but the imaginative amateur is bound by no 

 such restrictions ; he is free to conceive what 



