52 A. M. Mayer — Illuminating power of Flat 



Xot until the Quaternary era are certain proofs found of the 

 appearance of man. During the earliest epoch of this era his 

 implements and even his bones were entombed in the deep 

 auriferous gravels of California, while great uplifts, with fault- 

 ing and outflows of lava, were turning the rivers into new 

 courses Stone implements have also been found in the much 

 later Columbia formation in Delaware, which is here referred 

 to the time of continental uplift at the beginning of the 

 second Glacial epoch, and in the modified drift of Trenton, 

 ZST. J., of southern Ohio and Indiana, and of central Minnesota, 

 deposited during the stages of culmination and recession of the 

 ice-sheet of that epoch. Nearly of the same age, probably, is 

 the little image from an artesian boring through fluvial beds, 

 which enclose a lava-sheet, at Nampa, Idaho ; but the inhuma- 

 tion of the obsidian spear-head discovered by McGee in the 

 upper sediments of Lake Lahontan belongs to a still later and 

 indeed recent time. 



The accompanying table presents a correlation of the succes- 

 sive Quaternary epochs and formations, in descending order 

 from the present time to the beginning of this era, as reviewed 

 in the preceding pages. 



Art. TIL — On the illuminating power of Flat Petroleum 

 Flame* in various azimuths ; by Alfred M. Mayer. 



This paper contains the results of two series of measure- 

 ments of the amount of light given out in various azimuths 

 by two petroleum flames. One of these was the flat flame of 

 a Hitchcock lamp in which the combustion is maintained by a 

 blast of air driven against the flame by a fan moved by clock 

 work. This flame is not surrounded by a chimney. The other 

 flame was the flat flame of an ordinary petroleum lamp in- 

 closed by a chimney. 



The accompanying diagram expresses graphically the results 

 of these experiments. The flat flame is shown by the thick 

 line Fl. The polar coordinates of the closed curve A, B, C, D, 

 E. F. give, by the aid of the scale of candle power Fl, A, or 

 Fl. F, the amount of light given out by flame in various 

 azimuths. The zero of angle is in the plane, A, E, of the flat 

 flame. The inner and similar curve is the photometric curve 

 of the flat flame of an ordinary petroleum lamp. The circles 

 cutting these two curves are the photometric curves that would 

 be given by the respective flames, if the light which each 

 flame gives was equally distributed in all azimuths. 



