354 

NATURE 
[May 27, 1915 

63° each; the spectrum, extending from 2 45c-\ 590, 
measured 38:7 mm. The author directs attention to 
the peculiar form of the green ray in one part, indi- 
cating, as he says, a relation between prominences and 
the corona. In the determination of the wave-length 
of the green ray he deduces a value 5303:38+0:020, 
agreeing more closely with that of Campbell, namely, 
A 5303-26, than. that of Lockyer, A 5303-7. For another 
line, behaving after the nature of the green ray, of 
which he determines the wave-length, he deduces the 
value 4566-81. Details of the researches he proposes 
to publish at a later date. 
SPEcTROSCOPIC ANALYSIS OF THE N’KANDHLA AND 
OTHER MerTeoric Irons.—Dr. J. Lunt describes in the 
South African Journal of Science (April, vol. xi., 
No. 7) a spectroscopic analysis which he has made of 
the N’Kandhla meteorite and of other meteoric irons. 
The spectra were photographed in the four-prism star 
spectroscope of the Victoria telescope of the Royal 
Observatory at the Cape, the spark being obtained 
between -terminals of the meteoritic metal with an 
18-in. coal and large plate condensers. The object of 
the research was to try to detect the presence of 
elements which might have escaped recognition in the 
previous chemical analysis, and to compare the com- 
position of the N’Kandhla meteorite with that of four 
other meteoric irons, namely, the Great Namaqualand, 
Matatiele, Hex River, and Goamus. The result 
showed that cobalt, chromium, barium, and calcium 
were unmistakably present in the N’Kandhla, as well 
as in the other meteoric irons, though not detected 
chemically, and that no evidence was found of the 
presence of magnesium, platinum, and copper, traces 
of which were recorded in the chemical analysis. The 
non-metallic elements—carbon, sulphur, phosphorus, 
and chlorine—were recorded chemically, but furnished 
no spectroscopic evidence in the sparks, which were 
rich with the metallic elements. Dr. Lunt discusses 
in a series of paragraphs details with reference 
to the different elements found in these and other 
meteorites, and accompanies his paper with repro- 
‘ductions from strips of the spectrograms. 
MEASURES OF SOUTHERN DousLe Stars.—The fourth 
series of measures of double’ stars is  pub- 
lished. by Mr. Innes in Circular No. 24 of 
the Union Observatory, the previous series having 
appeared in the Transvaal Observatory Circular, 
No. 13, and the Union Observatory Circulars, Nos. 4 
and 14. The present series includes all pairs, more 
than 310 in number, for which satisfactory measures, 
equally divided between before and after meridian 
passage, have been made on at least two nightsby the end 
of 1914. The telescope employed was the 9-in. Grubb 
refractor. A great many of the pairs were measured 
for the first time. The measures were for the most 
part made by Mr. Innes and Mr. Van der Spuy, but 
the latter left the observatory early in the year to join 
the Aviation Corps of the Defence Force, and after- 
wards was with the British Army in France. 
MeasurinGc Heat From Stars.—In this column for 
February 25 attention was directed to a paper by Dr. 
W. W. Coblentz on a comparison of stellar radiometers 
and radiometric measurements on 110 stars. In the 
May number of the Popular Science Monthly, under 
the title, ‘‘ Measuring Heat from Stars,’’ he describes 
in a very interesting manner early attempts at measur- 
ing stellar radiation, and the method employed by him 
at the present time. The article gives a good insight 
into the extreme delicacy of the investigation, the 
great progress that has been made in recent years, 
and the important outstanding problems which will no 
doubt be solved when the instrumental equipment has 
advanced a stage or two further. 
NO. 2378, VOL. 95] 
RECENT WORK IN PALHZONTOLOGY. 
D. WALCOTT, among his studies entitled 
* “Cambrian Geology and Paleontology,” 
treats of a ‘a pre-Cambrian Algonkian algal flora” 
(Smithsonian Miscell. Coll., vol. Ixiv., No. 2, 1914). 
The horizon is that which has yielded the famous 
crustacean remains known as Beltina danai. The 
author urges that the abstraction of carbon dioxide 
from water by the action of blue-green alge and 
bacteria, such as Bacterium calcis of the Florida Keys, 
is a potent factor in the precipitation of oolitic and 
other forms of limestone, and he freely quotes recent 
work, such as that of E. J. Garwood, in support. He 
regards the dolomitisation of the older - limestones 
that may have been formed in this way as a secondary 
feature (p. 96). The author’s remarks, in answer to 

G. Abbott, contributed to Nature of December 31, 
1914, may imply some reconsideration of the part 
played by inorganic concretion in the structures here 
described as various species of Newlandia. Collenia 
(p. 98) becomes separated from Cryptozoén, the latter 
being regarded as appearing for the first time in the 
Cambrian period. 
G. R. Wieland has meanwhile published further 
studies on Ozarkian seaweeds and oolites (Bull. Amer. 
Mus. Nat. Hist., vol. xxiii., 1914, p. 237), dealing 
especially with Cryptozoon. He connects these Cam- 
brian forms with the far smaller Girvanella, as a 
“homogeneous assemblage’’ of sea-weeds, and enters 
into a somewhat confusing argument as to whether 
their silicification occurred early or late in geological 
history. This leads on to a discussion of the asso- 
ciated beds of siliceous oolite, which are held to be 
primary deposits, and especially characteristic of early 
Palaeozoic times (p. 255). The Jurassic oolites pre- 
served in flint at Portland, and the siliceous residues 
of the oolitic grains of ferrous carbonate in the 
pseudomorphous ironstones of Cleveland, are English 
evidences against this contention. Both Wieland 
(p. 248) and Walcott threaten us with a re-opening 
of the Eozoén question on algal lines, despite the 
work of Gregory and Johnston-Lavis on the lime- 
stone blocks of Monte Somma and several publica- 
tions on layer-structures from the osmotic point of 
view. 
G. R. Wieland is associated with Marion G. Elkins 
in a paper on ‘‘Cordaitean wood from the Indiana 
Black Shale” (Amer. Journ. Sci., vol. xxxvili., 1914, 
p. 65). The horizon is Upper Devonian, and the 

wood of the new species, Callixylon owent, is excep- 
tionally well preserved. From the great variety of 
structure in Devonian woods and the diversity of the 
ancient seed-types, the authors conclude that ‘‘if there 
is any past period which can be fairly singled out as 
the true age of gymnosperms it must be Devonian 
time.” ; 
H. Hamshaw Thomas has begun a_ systematic 
examination of the Middle Jurassic flora of Cleveland 
in Yorkshire, in which cycads are prominent 
(Quart. Journal Geol. Soc., London, vol. Ixix., 
p- 223). Wieland’s review of ‘‘the William- 
sonian tribe,” in which British specimens from the 
Yates collection are utilised, will no doubt be referred 
to as the work goes on (Amer. Journ. Sci., vol. xxxii., 
p- 433). Both authors point out how we are in- 
debted to Nathorst for additions to our knowledge of 
the cycad fruits of Yorkshire. F. H. Knowlton com- 
pares the Jurassic flora of Cape Lisburne, Alaska 
(U.S. Geol. Survey, Prof. Paper, 85-D, 1914), with 
that described by Heer and Seward from Amurland 
in eastern Siberia, and takes the opportunity for a 

| brief review of the Arctic and Antarctic occurrences 




