282 
NATURE 
[ Fan. 19, 1882 
The comparative explosive force of the two gas’s calculated 
in the usual way is as 3°4: I, z.e¢. coal-yas has 3°4 times more 
energy than the Dowson gas. But because the combustion of 
carbon monoxide proceeds more slowly than that of carburetted 
hydrogen gases, and because the diluents present in the cylinder 
affect the weaker gas more than the coal-gas, in practice, with 
an Otto engine five volumes of the Dowson gas are used for one 
volume of coal-gas. 
A table was given showing all the working expenses of an 
Otto gas-engine indicating 30 horse-power, and driven by the 
Dowson gas for 300 days of nine hours each, so that these 
expenses might be compared with those given for the steam- 
engine and the gas-engine worked with coal-gas. These figures 
showed that a gas-engine worked with Dowson gas costs about 
45% per cent. less than when worked with coal-gas at 3s. per 
1000 cubic feet, and about 474 per cent. less than a steam-engine 
of the portable type, after allowing in each case for repairs and 
depreciations, and interest on capital outlay. The most striking 
feature, however, was that with a steam-engine consuming 6 lbs. 
of coal per indicated horse-power per hour, and without adding 
any allowance for fuel used in getting up steam, and after work 
is done, 217 tons of coal are required to give the same power as 
39 tons of coal converted into gas by the Dowson process. This 
represents a saving of about 88 per cent. in the weight of fuel. 
Another practical consideration was that the quantity of the 
Dowson gas required to give the equivalent of 1000 cubic feet 
of coal-gas was only 24 to 27 per cent. of the weight of the coal 
necessary for the latter. A further point of great interest is 
that a series of trials made with 34 horse-power (nomimal) Otto 
engines driven by the Dowson gas, have proved that 1 horse- 
power (indicated) is obtained with a consumption of gas derived 
rom 1°46 dbs. of coal after allowing for the gas burnt in the manu- 
facture of the gas as well as Io per cent. for impurities and waste 
of the coal. With gas-engines of larger power the loss due to 
friction is proportionally less, and the consumption of gas per in- 
dicated horse-power is less, thus with a 16 horse-power (nominal) 
engine which can indicate up to about 40 horse-power, the 
Dowson gas required would be about 90 cubic feet per indicated 
horse-power per hour, and this would give a consumption of 
coal of only 1'2 per indicated horse-power per hour. 
Moreover, with a cheap heating gas not only can a saving in 
the motive power be effected for electric lighting, but this gas 
can also be used for domestic and industrial purposes, such as 
cooking and heating. It burns without smoke, so that when it 
is used in districts where there are many factories, or where 
much coal is consumed, not only will a great saving be effected, 
but in addition there will be freedom from a dark depressing 
atmosphere—the presence of which, the lecturer remarked, was 
the bane of London, and the absence of which formed the 
greatest charm of Paris. 
NEW BIRDS FROM THE SOLOMON ISLANDS 
At a recent meeting of the Linnean Society of New South 
Wales Mr. E. P. Ramsay, F.L.S., &c., Curator of the 
‘Australian Museum, read descriptions of the following six new 
birds from the Solomon Islands :— 
Astur versicolor.—The whole plumage above and below is of 
a bluish slate-black, the base of the quills below ashy white. 
The length is about 17 inches, the wing 9°7. The immature 
nd young birds are also described, 
The adult male of Nasiterna finschit is described as having a 
crimson patch on the abdomen; otherwise like the female, 
which alone was previously known, ‘The young of this species 
is also described ; they differ in having a rosy tint on the cheeks. 
A fine pigeon is described, and called lanthanas philippane ; 
it is allied to Z pallidiceps, but is not so dark in the plumage, 
being of a bluish slate colour, except the head and throat, which 
are white, with an opaline rose tint ; the metallic reflections of 
the body are rose and light green ; length 15 inches, wing 94 
inches, Two other pigeons of the genus Ptilopus have been dedi- 
cated to officers of Her Majesty’s Navy. 
ftilopus richardsii,—A very beautiful and distinct species, 
having the head, neck, and all the under surface French gray, a 
very faint lavender crown, the wings and tail green; the former 
have a rosy carmine oblong or lanceolate spot on the scapulars ; 
the latter has a terminal band of pale yellow. The nest, eggs, 
and young of this species are also described. 
Piilopus lewisit.—This bird was previously described in 
the same journal, and referred to Ptilopus viridis, and after. 
wards determined as the female of Prilopus eugenia (Gould). A 
large series of both sexes and the young show it to be a new 
species. The general colour is green, the chest with a large 
patch of violet-purple. A description will be found in the Pro- 
ceedings of the Linnean Society of New South Wales, vol. iv. 
1879, p. 73. 
ftilopus johannis of Sclater is stated to be the male of 
P. soloménensis of Gray, and to = P. ceraseipectus of Tristram. 
A fine new Chalcophaps has been named after its discoverer, 
Mr. Alex. Morton, Cha/cophaps mortoni; it is like C, chryso- 
chlora, but larger, and has no band on the shoulder ; the young 
had been previously described under the name of C. chryso- 
chlora, var. sandwichensis ; the name is now altered to that of 
mortoni, and the adult described. 
Myiagra cervinicauda, Tristtam.—The male of this species is 
described, the type-specimen being a female; it belongs to the 
M. plumbea group of the genus, : 
Sternoides minor.—A smaller species than either of the pre- 
viously known species, and differs in having a more curved 
bill, and all the secondaries, as well as the primaries, of an 
eee rae a tint. Length about 74 inches, wing 4°3, tarsus 
I inch. 
A second paper by the same author contains a description of 
a new honey-eater of the genus Plectorhyncha, or of a new genus 
very closely allied to it. This species, which is of a uniform 
dull fulvous brown, has been named P. /ulviventris. It comes 
from the south-east coast of New Guinea. Length about 
8 inches, wing 3°8, tail 3°2, tarsus 1 inch. 
Mr, Kamsay stated that the trustees of the Australian Museum 
had recently received large collections from their collector in the 
Solomon Islands, and were daily expecting further consignments 
from New Guinea. 
SCIENTIFIC SERIALS 
Annalen der Physik und Chemie, No. 12, 1881.—On the 
interference of phenomena of thin plates with special reference 
to the theory of Newton’s rings, by W. Fenssner.—On the 
dispersion of aragonite in an arbitrary direction, by V. v. Lang. 
—Remarks on Herr Lamansky’s works on fluorescence, by O. 
Lubarsch.— Upper limits for the kinetic energy of moved elec- 
tricity, by H. R. Hertz.—On disaggregation of electrodes by 
positive electricity and explanation of the Lichtenberg figures, 
by E. Reitlinger and Fr. Wiachter.—Researches on the height 
of the atmosphere and the constitution of gaseous bodies (con- 
tinued), by A. Ritter.—Contributions to the theory of electro- 
magnetism, by W. Siemens.—Researches on the volume con 
stitution of liquid compounds, by H. Schréder.—On the 
theoretical determination of vapour pressure and the volumes of 
vapour and liquid, II., by R. Clausius.—On an equation which 
satisfies the kinetic energy of vibratory movements, by S. 
Oppenheim, 
Journal de Physique, December, 1881,—Hydroelectric and 
hydromagnetic phenomena, by C. A. Bjerknes.—Variation of 
indices or refraction of gypsum with temperature, by H. Dufet. 
—On the measurement of temperatures by means of the mercury 
thermometer, by M. Pernet.—On the singular polarisation ot 
electrodes, by A. Solokoff.—Discourse of M. Dumas at the 
International Congress of Electricians, 
Rivista Scientifico-Industriale, December 15, 1881.—Displace- 
ments and deformations of the spark in air by electrostatic 
action, by R. Righi—On some curious conformation of the 
spark in air, by the same,—Endogenous origin of the roots of 
plants, by S. Briosi. 
THE last two parts of the Memoirs (Trudy) of the St. Petersburg 
Society of Naturalists contain, besides the minutes of proceed- 
ings, the following interesting papers (vol. xi, fascicule 2) :—A 
preliminary report on the structure of corals, and on the origin 
and development of the egg of the A/edusa /eucope before fructi- 
fication, by K. S, Mereshkovsky.—Materials for the flora of the 
Onega region, by A. K. Hiinter; and of the neighbourhood of 
Povenets, in the government of Olonetz, by Chr. Gobi.—(Vol. 
xii. fascicule 1):—A geological description of the neighbour- 
hoods of Krasnoye and Tsarskoye Selo, by R, Kudryavtseff and 
J. Lebedeff (with map and plates).—On the aérial roots of the 
‘Acanthoriza aculeata, by K. Friedrich (with plates).—On the 
influence of light on mushrooms, by K. Regel.—On the Imatra 
waterfall and Imatra stones, by P. Venukoff.—Report on the 
expedition to the White Sea, by L. Tsenkoysky. This volume 
: 
