37o 



NA TURE 



[August 1 6, 1883 



lating motion of the earth's crust are referred to by Mr. 

 George Darwin in his Report to the British Association 

 in 1882. One of them was made by M. Magnus Nyren 

 at Pulkova, who, when engaged in levelling the axis of a 

 telescope, observed spontaneous oscillations in the bulb 

 of the level. 



This was on May 10 (April 28), 1877. The complete 

 period was about twenty seconds, the amplitude being 

 1 ""5 and 2". One hour and fourteen minutes before this 

 he observes that there had been a severe earthquake at 

 Iquique, the distance to which in a straight line was 

 10,600 kilometres, and on an arc of a great circle 12,500 

 kilometres. 



On September 20 (8) in 1867 Mr. Wagner had observed 

 at Pulkova oscillations of 3", seven minutes before which 

 there had been an earthquake at Malta. 



On April 4 (March 23), 1868, an agitation of the level 

 had been observed by M. Gromadzki, five minutes before 

 which there had been an earthquake in Turkestan. 



Similar observations had been made twice before. 

 These, however, had not been connected with any earth- 

 quakes, at least — Mr. Darwin remarks — with certainty. 



Like phenomena are mentioned by M. S. di Rossi, in 

 his "Meteorologica Endogena.'' 



Thus on March 20, 1 8S 1 , at 9 p.m , a watchmaker in 

 Buenos Ayres observed that all his clocks oscillating 

 north and south suddenly began to increase their ampli- 

 tude, until some of them became twice as great as before. 

 Similar observations were made in all the other shops. 

 No motion of the e:'rth was detected. Subsequently it 

 was learnt that this corresponded with an earthquake in 

 Santiago and Mendcza. 



Another remarkable example illustrating the like phe- 

 nomena are the observations which were made on 

 December 21, iS6o, by means of a barometer in San 

 Francisco, which oscillated, with periods of rest, for half 

 an hour. No shock was felt, nor is it likely that it was 

 a local accident, as it could not be produced artificially. 

 On the following day, however, a violent earthquake was 

 experienced at Santiago. 



This brings me to the end of the few important 

 illustrations of the phenomena of earth pulsations which 

 I have at my disposal. With a little trouble I have 

 no doubt that these might be greatly multiplied. As 

 they stand, however, I think that they are quite suffi- 

 cient to convince us of the existence of phenomena 

 which hitherto have been almost entirely overlooked. 

 That disturbances of the vertical are from time to 

 time produced by long pulse-like waves can, with 

 these examples before us, hardly be doubted. It must, 

 however, be noted that they are of a different order to 

 those phenomena which were so carefully sought for by 

 the Darn-ins at Cambridge. John Milne 



Tokio, Japan 



ON THE SUPPOSED HUMAN FOOTPRINTS 

 RECENTLY FOUND IN NEVADA ' 



TOURING the past summer various accounts have been 

 ■^— ' published of the discovery of human footprints in 

 sandstone ] ear Carson, Nevada. The locality is in the 

 yard of the State prison, and the tracks were uncovered 

 in quarrying stone for building purposes. Many different 

 kinds of tracks were found, some of which were made by 

 an animal allied to the elephant ; some resembled those 

 of the horse and the deer; others were apparently made 

 by a wolf. There were also tracks made by large birds. 

 The footprints occur in series, and are all nearly in the 

 same horizon. Some of the smaller tracks are sharp and 

 distinct, but most of the impressions are indefinite in out- 

 line, owing apparently to the fact that the exact surface 

 on which they were made is not usually exposed. 



1 Abstract of a paper read before the National Academy of Science*, at 

 New York, November 17, 1882. 



The supposed human footprints are in six series, each 

 with alternate right and left tracks. The stride is from 

 two and a half to over three feet in extent. The individual 

 footprints are from eighteen to twenty inches in length, 

 and about eight inches wide. The distance between the 

 line of right-hand and left-hand tracks, or the straddle, is 

 eighteen to nineteen inches. 



The form and general appearance of the supposed 

 human tracks is shown in Fig. 2, which is a reduced copy 

 of one of the impressions represented by Dr. W. H. 

 Harkness, in his paper before the California Academy of 

 Sciences, August 7, 1882. The shaded portion was 

 restored by him from other footprints of the series. A 



Left hind foot of Mylodon robustits (after Owen). One-sixth 

 natural size. 



copy of this impression was given also by Prof. Joseph Le 

 Conte, in his paper before the same Society, August 27, 

 1882. 



The size of these footprints, and especially the width 

 between the right and left series, are strong evidence that 

 they were not made by men, as has been so generally 

 supposed. 



A more probable explanation is that the impressions 

 are the tracks of a large sloth, either Mylodon or Moro- 

 therium, remains of which have been found in essentially 

 the same horizon. In support of this view it may be said 

 that the footprints are almost exactly what these animals 

 would make if the hind feet covered the impressions of 



Fig. a.— Left footprint at Carson (after Harkness). One-sixth natural siie. 



those in front. In size, in stride, and in width between 

 the right and left series of impressions, the footprints 

 agree closely with what we should expect Mylodon or 

 Morotherium to make. In Fig. 1 the bones of the left hind 

 foot of a species of Mylodon are represented, the figure 

 being reduced to the same scale as the accompanying cut, 

 Fig. 2, of one of the supposed human footprints. 



The geological horizon of these interesting footprints 

 is near the junction of the Pliocene and Quaternary. The 

 evidence, at present, appears to point to the Equus beds 

 of the upper Pliocene as the nearest equivalent. 



Since the above communication was read, the writer has 

 had an opportunity of examining photographs and casts 

 of the Carson footprints, and is confirmed in his opinion 

 that the supposed human tracks were made by large 



