POPULAR MISCELLANY. 



281 



ciation, have been observed from the very 

 earliest times, and are so great that they can 

 be detected with very simple apparatus. 

 These effects are due to exterior causes, and 

 consist in a displacement of the axis of the 

 earth in space, and a consequent wandering 

 of the pole among the stars. The action of 

 internal forces in the earth would be to pro- 

 duce a displacement in the rotating body 

 itself. A deviation of the rotational axis 

 from the principal axis of inertia would cause 

 a rotation of the pole round the principal 

 axis of inertia. Such a rotation would have 

 a period of nearly ten months, and could be 

 best detected by continuous and active ob- 

 servations of latitude at various observato- 

 ries. Measurements were made as early as 

 the middle of this century, but gave no defi- 

 nite results, the ten-monthly period being 

 marked by other disturbances due to cur- 

 rents and circulations in the atmosphere, 

 oceans, and rivers. Four years ago the In- 

 ternational Geodetic Union secured co-opera- 

 tion of observations, and this, together with 

 an expedition to Honolulu, has led to defi- 

 nite results. These show that the north pole 

 wanders through about fifty feet between its 

 extreme positions. 



Bactericidal Solar Rays. Although in- 

 vestigation has not been idle, experimenters 

 have not been wholly agreed as to the exact 

 property or field of the sun's rays which is 

 most efficient in action on bacteria and fungi. 

 The inquiry has been continued by Prof. H. 

 Marshall Ward, to whom the thought oc- 

 curred in the course of his work that the 

 most direct answer to the question, Which 

 rays are the most effective ones ? might be 

 best obtained by shining the solar spectrum 

 directly upon the film of spores, and making 

 it record the effects by their subsequent be- 

 havior, according as the different groups of 

 rays fell upon them in other words, by ob- 

 taining a photograph of the spectrum in liv- 

 ing and dead bacteria. The results showed 

 conclusively that the rays that kill the bac- 

 teria are the blue and violet ones. An ob- 

 servation was made during the investigation 

 which may go far to account for the unsat- 

 isfactory character of the determinations of 

 former experiments. The chief difficulty to 

 be overcome was the great weakening of the 

 intensity of the dispersed rays of the beam 



of light decomposed to form the spectrum 

 a weakening caused by the distribution of 

 the incidence of the rays over a larger area 

 and by their absorption and reflection in 

 passing through the lenses and prisms. It 

 was found also, in working with the electric 

 light, that the power of the blue and violet 

 rays was further impaired in other words, 

 that they were stopped by the material 

 (glass) through which they had to pass. The 

 effect of the glass was practically the same 

 as that of mist or haze in the atmosphere, 

 which so filters out the blue-violet rays that 

 the light of a dull day was of little effect in 

 the author's experiments. These difficulties 

 were overcome by using quartz instead of 

 glass, with which it was possible to obtain a 

 very pure spectrum sufficiently rich in blue 

 and violet rays to kill the spores in a few 

 hours. The author found it easy to obtain 

 satisfactory results in the summer with the 

 solar rays, even with glass lenses, mirrors, 

 etc., and exposures of five or six hours, but 

 in winter the exposures required to be so 

 long as to be almost impracticable. 



Work of the Peabody Museum, The 



Curator of the Peabody Museum of American 

 Archaeology and Ethnology calls attention, in 

 his report for 1893-'94, to the lack of room 

 in the museum. Several collections made 

 under the curator's direction have been se- 

 cured. Besides a generous gift of money, 

 Mr. Clarence B. Moore has contributed a good 

 representative collection of the singular pot- 

 tery which he obtained from a mound in 

 Florida, and other objects of interest from 

 the burial and shell mounds of that State. 

 The publication of Mr. Nuttall's memoir has 

 been provided for, and the work has been 

 held in press for the incorporation of newly 

 discovered facts. Space has been provided 

 for the collections of archaeological, histor- 

 ical, and educational objects and relics made 

 by the late Mrs. Hemenway, of which Mr. J. 

 Walter Fewkes is in charge. The collection 

 of Mr. Frederick H. Rindge, deposited in the 

 museum, contains the finest and most exten- 

 sive lot of obsidian implements ever brought 

 together from the Klamath country. Some 

 of the chipped implements are remarkable 

 for their size, and others for their beautiful 

 finish. The collection also includes gems 

 of workmanship in stone, bone, and ivory 



