process know what has already been done; while the 
general public ought not to remain ignorant of what 
legitimately belongs to them, and which, after the ample 
reward he has received for his inventions, the author 
desires they should enjoy without any restrictions. The 
author of the second paper holds that the making of steel 
in small quantities is a step in the wrong direction, be- 
cause the steel cannot be made so cheaply ; but, as he 
points out, itis to the interest of owners of small blast plant 
to possess the means of converting their product into steel, 
and of ironworkers who cannot find work for their 
puddling furnaces to make steel enough to keep their 
machinery at work rather than be dependent on larger 
firms for a supply of ingots. An American steel-maker 
in the discussion drew attention to the circumstance that 
in the United States, when the rail trade was brisk, it 
was impossible for the smaller works to obtain Bessemer 
ingots at all, and that they had to introduce small plant 
for self-preservation. From the statement of opinion it 
was evident that there was necessity for the original 
Bessemer converters and the smaller modified forms. 
Mr. Frederick Siemens’s paper on combustion with 
special reference to practical requirements draws atten- 
tion to the means necessary for adoption to insure perfect 
combustion. The gases must be supplied in the exact 
chemical proportion in which they are required for com- 
bustion; they must be brought together in such a 
manner that the different molecules which have to 
enter into combination may readily do so, whilst every 
thing must be avoided which interferes with the motion 
of the gases while combustion is proceeding. 
The author enters in detail on the way in which gases 
should be brought together, he explains that the-Bunsen 
burner, though theoretically perfect, cannot be=adyan- 
tageously carried out in furnaces, as the flame of a 
Bunsen burner being almost non-luminous owing ‘to free 
carbon not being liberated during~ combustion, has but 
little radiating power, and must in consequence transmit 
its heat by direct contact only. As the gases cannot 
generally be mixed before combustion, it-is-a matter of 
great importance how they are -brought :together..when 
combustion commences, a mean being necessary between 
a too intimate mixture, producing a short flame having 
great heating but little radiating power, and an imperfect 
mixture, which does not allow of combination properly 
taking place. The third means necessary is the one to 
which the author has frequently drawn special attention, 
because neither the employment of gases in proper 
proportion, nor their proper mixture is sufficient to insure 
perfect combustion Z/ the disturbing influences of surfaces 
ts allowed to interfere to prevent combustion, or to dis- 
sociate particles of gas already combined. In the author's 
view the dissociation caused by hot surfaces is of various 
kinds, and takes place at different temperatures. At a 
comparatively low temperature, dissociation of hydro- 
carbons takes place, the carbon being liberated in the 
solid form as soot. At a moderately high temperature 
carbonic oxide is dissociated into solid carbon and car- 
bonic acid gas; at a higher temperature the products of 
combustion begin to dissociate, steam splitting up into 
hydrogen and oxygen, and lastly, at a still higher tem- 
perature, depending upon the kind of surface with which 
the products of combustion come into contact, carbonic 
acid splits up into solid carbon and oxygen. From this 
it will be seen that dissociation has the effect of setting 
carbon free, and to its influence the formation of smoke 
is largely due. 
The author then proceeded to show that smoke within 
a furnace chamber is caused by flame in the first instance 
touching surfaces which then become enveloped in a 
dense cloud of dissociated carbon, which prevents the 
heat rays from reaching them. The author illustrated 
his remarks by means of a gas-burner proposed to be 
used instead of the English fire-place, by the use of which 
NATURE 
[ Oct. 14, 1886 
it is stated that heat is much more uniformly distributed 
throughout a room. The flame was intensely bright and 
hot, due as explained to its being fed with hot air, and 
working with free development of flame that is entirely 
out of contact with any surfaces. The gas stove afforded 
considerable interest to the members, and the author by 
special request explained its mode of action. 
The papers read on the Jast day of the meeting were 
two by Mr. F. Gautier, of Paris, on the casting of chains in 
solid steel, and on silicon in foundry iron. Hitherto 
chains have been made of wrought iron, the difficulty in 
the various processes of manufacture being the difficulty 
of securing a good weld; this, according to the author, is 
now overcome by a process of Messrs. Joubert and Leger, 
of Lyons, which combines chilled casting and instan- 
taneous removal from the moulds. In the second paper 
the writer refers to the advantage of silicon in producing 
homogeneous steel and pig iron castings and improving 
foundry pig; he also drew attention to the intro- 
duction of ferrosilicon in French foundry practice. 
The author’s views were in general supported by 
the members in discussion. Mr. F. W. Harbord’s 
paper, “ On the Elimination of Silicon, Phosphorus, &c., 
in the Basic Open-hearth Process,” gave evidence that 
soft steel of the very finest quality could be produced 
from inferior material by this process, whilst the conditions 
of working in the Siemens furnace are peculiarly favour- 
able to its production. | Surgeon-Major Hendley’s paper, 
“On the Process employed in Casting Brass Chains at 
Jeypore, Rajputana,” was contributed by Mr. C. Purdon 
Clarke, and illustrated by samples. The papers on 
“Chrome Steel,” by Mr. Brustlem, and on “ American 
Blast Furnace Practice,” by Mr. F. W. Gordon, Phila- 
delphia, were put off to the next meeting. 
NOTES 
WE regret to learn that Baron von Miiller retires from the 
directorship of the Melbourne Botanic Gardens in June next. 
THE death is announced of M. Dubosc, a Paris optician, 
who assisted M. Léon Foucault in all his constructions, and 
especially in the organisation of his automatic electric lamp. 
Tne Laboratoire d’Electricité created with the surplus of the 
Electrical Exhibition of 1881, held in the Palais de l’Industrie, 
will be erected on the site of the old Collége Rollin, on 
ground granted by the City of Paris. It will be open to elec- 
tricians of every nation, and governed by the International 
Society of Electricians. 
AN ordinary General Meeting of the Institution of Mechanical 
Engineers will be held in the Yorkshire College, Leeds, on 
Monday, October 18, by invitation of the College authorities, in 
celebration of the opening of the Engineering Department of the 
College. The following papers will be read and discussed, as 
far as time permits :—‘‘ On Triple-Expansion Marine Engines,” 
by the late Mr. Robert Wyllie, of Hartlepool ; ‘‘ Notes on the 
Pumping Engines at the Lincoln Water-Works,” by Mr. Henry 
Teague, of Lincoln; ‘‘ Description of a Portable Hydraulic 
Drilling Machine,” by M. Marc Berrier-Fontaine, of Toulon. 
THE Commission of the French Budget having adopteJ without 
reduction all the proposals of the, Government for the Algerian 
provinces, the construction of the large instruments for Bouzareah 
Observatory will be continued, and inspection of the heavens 
will be conducted on a large scale at Algiers. An observer 
connected with the Trocadero Observatory has been appointed 
to assist M. Trépied, and left Paris last week for his destination. 
THE photographie method has been established at the Algiers 
Observatory for the sun. Nine times out of ten the operation 
has been successful. 
