December 10, 1«86.] 



SCIENCJB. 



529 



series of shore-deposits left by the receding ice of 

 the last glacial epoch. Mr. Gilbert described 

 minutely the manner in which these old beaches 

 were buUt up by moving gravel one after another 

 by a series of inverted imbrications or overlap- 

 pings, and relegated the hearth in question to one 

 of the first of them laid down in this particular 

 series, roughly estimating the time at about seven 

 thousand years ago. 



Mr. Gilbert was followed by Mr. W. J. McGee, 

 who described the finding of an obsidian spear- 

 head or knife, four inches long and beautifully 

 chipped, in Walker River Canon, Nevada. The 

 greatest care was taken in removing this find, and 

 all the intelligent forethought which a trained 

 geologist could exercise was used to mark the 

 exact conditions of the case. Not the slightest 

 evidence of intrusive burial or bank veneering ap- 

 peared, and Mr. McGee was convinced that the 

 weapon was deposited when the stratum contain- 



THRBSHING-SLEDGE. 



ing it was laid down, the time being approxima- 

 tively that of Mr. Gilbert's find. 



Mr. John Murdoch reported at the same meeting 

 the discovery of a pair of wooden snow-goggles, 

 like those now used by Eskimo to protect the eyes 

 from the glare of the sun and driving snow, in a 

 shaft which his party dug at the depth of twenty- 

 seven feet below the surface. Mr. Murdoch's dis- 

 covery made an interesting connecting link in the 

 interpretation of Mr. Gilbert's hearth. 



Two of these finds were neolithic of the most 

 advanced type, and located at the close of the last 

 glacial epoch : they certainly start ten times more 

 questions than they answer. 



The national museum has lately acquired two 

 specimens from different parts of the world, which 

 introduce an element of confusion into archeologi- 

 cal speculations. Both of them represent the use 

 of stone implements of the very rudest type by 

 peoples above savagery. 



One of these specimens is a tribuliim, or thresh- 

 ing-sledge, from Tunis. It is a low sledge or drag 

 made of two planks, seventy inches long, nineteen 

 inches wide, and ten inches thick, turned up 



slightly at the front, and narrowed like a square- 

 toed shoe. Three stout battens across the upper 

 side are securely nailed down. On the under side, 

 just where the flat portion commences, are seven- 

 teen strips of iron, like dull knife-blades, ar- 

 ranged in two rows quincuncially. Along each 

 margin of the under side are four similar dull 

 blades. All the remainder of the bottom is occu- 

 pied with sixteen rows of stone teeth, sixteen in a 

 row, arranged quincuncially and projecting about 

 an inch. These teeth are nothing but bits of 

 jagged quartz, and, if picked up independently of 

 then- environment, would hardly be regarded as 

 wrought by human hands. 



The other ' paleolithic ' civilized implement is a 

 Spanish Rallador, or grater, from Britisli Hon- 

 duras. It consists of a plank of hard wood eigh- 

 teen inches long and ten inches wide, into which 

 have been driven nearly two thousand bits of 

 quartz no larger than tiny arrow-heads, only they 

 are not chipped in the least, and are less shapely. 



With such material as the Gilbert hearth, the 

 McGee spear-head, the Murdoch spectacles, the 

 Tunis tribulum, and the Honduras grater accumu- 

 lating around us every day, the question does not 

 seem to be as to the antiquity of man, but whether 

 or not archeology will help us in ascertaining his 

 pristine condition on this continent. Dismissing 

 the tribulum (the stone furniture of one of them 

 would stock an African paleolithic cabinet), we 

 have evidence which would satisfy some minds 

 that at the end of the glacial epoch there lived 

 men who built fires, chipped obsidian most beauti- 

 fully, and wore snow-goggles, while in the nine- 

 teenth centmry A.D. men were still in the lowest 

 story of the stone period. O. T. Mason. 



THE HEALTH OF NEW YORK DURING 

 OCTOBER. 



The health department estimates that on this 

 1st of October the population of the city of New 

 York was 1,449,958. Of this number, 2,977 died 

 during the month, which was an increase of 210 

 as compared with September : 1,275 of these 

 deaths occurred among children under five years 

 of age. There was a marked reduction of deaths 

 from diarrhoeal diseases. The maximum mor- 

 tality from this cause was in the month of July, 

 when no less than 1,382 deaths took place ; in 

 August this was reduced to 705 ; in September, 

 to 479 ; and in October, to 234, only about one- 

 sixth the mortality of July. Fifty-eight more 

 deaths are chargeable to consumption than in 

 the preceding month, although the average for 

 October is about that of other months of the year. 

 But 18 persons died from scarlet-fever, — a small 



