May 8, 1 9 1 3 



NATURE 



2 53 



authors refer to the previous work of Sir Norman 

 Lockyer at South Kensington, who showed that in 

 the case of Nova Persei its bright-line spectrum was 

 composed for the most part of « Cygni, or enhanced 

 lines. Thus the origins of most of the nova lines at 

 this stage of its history will now be considered as 

 more definitely settled. The paper is accompanied by 

 an excellent plate showing the nova spectrum and 

 comparison spectra. 



Radial Velocities of Stars with the Prismatic 

 Camera.— Some time ago Prof. E. C. Pickering sug- 

 gested a means of determining the radial velocities 

 of stars from prismatic camera photographs by insert- 

 ing in the optical train a medium which produced 

 a sharp absorption line in the stellar spectrum. Mr. 

 R. W. Wood found out, that the absorption line of 

 neodvmchloride at M-73 A - u - m a w e ak solution was 

 of prominent sharpness. Prof. Schwarzschild has now 

 used this filter in connection with an objective prism, 

 the instrument being a Zeiss triplet of 150 mm. 

 aperture and 1494 mm. focal length, and a prism 

 of the same aperture giving a dispersion from H7 to 

 K of 103 mm. He placed the cell a few millimetres 

 in front of the photographic plate, the former being 

 about 8 mm. in thickness, and containing a weak 

 solution, the proportion being 1 to 6. In Astr. Nadir., 

 No. 4646, he gives an account of the results he 

 secured, using the star °t Coronas borealis, the 

 spectrum of which is not very favourable for the 

 research, as the lines are hazy, though the orbit is 

 well known. At least four spectra near each other 

 were taken on the plate, and photographs were 

 secured on eighteen evenings. Prof. Schwarzschild 

 describes in detail the methods of measurement and 

 reduction, and states that the probable error of the 

 mean of six spectra in an evening is ±5-7 km. /sec, 

 and the probable error of a single spectrum ± 13 

 km. /sec. He points out that Mr. Jordan, with a 

 photograph taken with a slit spectroscope, obtained 

 probable errors of 4-2 to 5-5 km. /sec, according to 

 the kind of plate used, and Mr. Cannon a value 

 amounting to ±5-4. The observations corroborate 

 Jordan's period of 17-36 days. 



Meteorite from Kansas. — A reprint from the Pro- 

 ceedings of the U.S. National Museum (vol. xliv., 

 p. 325") contains an account of a newly found meteorite 

 from near Cullison, Pratt County, Kansas, by George 

 P. Merrill, head curator of eeology of the National 

 Museum. The stone is described as having struck the 

 earth in December, 1902, but it was not found until 

 191 1. Mr. Merrill was thus confronted with the 

 doubt as to whether the stone was the one actually 

 seen to fall, but he found that a thin section indicated 

 the meteoritic nature of the stone at once. Besides 

 showing special interest from the diversity of the 

 thondritic forms which it carried, another feature 

 was a somewhat indistinct wavy banding visible only 

 on a polished surface of a section. The paper, be- 

 sides giving illustrations of the stone as found and 

 polished surfaces, contains chemical and mechanical 

 analvses of the stone, and the following is the com- 

 position of the stone in bulk, omitting percentages 

 of substances less than unity : — 



directed especialh to two communications. The first 

 is the address of the president of the society, Prof. 

 L. B. Stewart, delivered at the annual meeting, and 

 has for its title, "The Structure of tin- I niverse." 

 In this be brings together most of the more important 

 recent researches relating to this subject, including 

 such investigations as deal with star streams, 

 proper motions of separate groups, absorption in 

 space, &c. The second article is a delightful account 

 of Mr. John A. Brashear's visit to the home of Dr. 

 Thomas Dick, the Christian philosopher and astro- 

 nomer. Mr. Brashear came over in 1911 for the fifth 

 centenary celebration of St. Andrews University, and 

 after listening to the opening addresses, as he says, 

 " I could not resist the temptation to slip away " and 

 make a visit to Broughty Ferry, near Dundee, the 

 home of Dr. Dick. Mr. Brashear is full of enthu- 

 siasm of the reception he received at the hands of 

 the present owners, and brings together some very 

 interesting notes relating to episodes in Dr. Dick's 

 career; numerous illustrations accompany his com- 

 munication. 



Royal Astronomical Socifty of Canada. — The 

 Januarv-Februarv number of the Journal of the Royal 

 Astronomical Society of Canada (vol. vii., No. 1) con- 

 tains much interesting reading, and attention is 

 VOL. 91] 



THE ERUPTION OF THE K AT MAI 

 VOLCANO, ALASKA, ON fUNE 6, 1912. 



IN The National Geographic Magazine for February 

 of the present year there appears a very interest- 

 ing account of the eruption of Katmai, in Alaska, 

 which commenced on June 6, 1912. The Katmai 

 Volcano (7500 ft.) is one of ten or twelve more or less 

 active volcanoes known to exist in the Alaskan penin- 

 sula, though probably a still greater nvimber occur 

 in the adjoining Alaskan islands. The report is 

 furnished by Mr. G. C. Martin, who was dispatched 

 by the National Geographic Society of Washington 

 to collect information as soon as the news of the 

 eruption arrived by telegraph. This report, which is 

 illustrated by a map and numerous photographs, shows 

 that the outburst resembled in all its main features 

 that of Krakatoa in 1883, though, happily, owing to 

 the very sparse population of the district, the damage 

 done was comparatively small, and no human lives 

 were lost. No lava-streams are recorded as having 

 been seen, but the eruption, which included three 

 outbursts of excessive violence within two days, con- 

 sisted in the discharge, first of pumice, and after- 

 wards of dust of gradually increasing degrees of fine- 

 ness. In the sea, twenty miles from the volcano, float- 

 ing pumice was accumulated to such an extent that 

 men could walk upon it. At Kodiak, 100 miles from 

 the volcano, dust fell, causing complete darkness for 

 sixty hours, and accumulated to a general depth of 

 10 to 12 in. Roofs were broken down by the weight 

 of this dust, and houses wrecked by the avalanches 

 of it which descended from the hills. Dust was re- 

 corded as having fallen 900 miles away, and if vessels 

 had been in those seas it would probably have been 

 noticed much farther off. Probably great changes 

 were produced in the volcano itself, for one observer 

 declared that half the mountain was gone. 



This report is followed in the same journal by an 

 article from the pen of Dr. C. G. Abbot, the director 

 of the Astrophysical Observatory of the Smithsonian 

 Institution, Washington. From observations made 

 by himself in Algeria, where he happened to be at the 

 time of the Katmai eruption, and from communica- 

 tions he received from Mount Wilson, in California, 

 Mount Weather, in Virginia, and other localities in 

 different parts of the p-lobe, he infers that a similar 

 world-wide diffusion of the fine volcanic dust took 

 place as was observed in the case of the Krakatoa 

 eruption, and he discusses the auestion, " Do Volcanic 

 Explosions Affect our Climate?" 



NO. 2271 



