400 
POPULAR SCIENCE REVIEW. 
range of temperature, which is not the case with ordinary steel or copper. 
A plate of 18 inches diameter has been forced through a series of dies 
until it has formed a tube 13 feet long and If inch diameter, without 
any crack or flaw. In drilling a circular hole into a plate of Bessemer 
steel, continuous shavings are formed, whereas in copper, or any other 
metal, the shavings break into pieces inch long. These sheets of the 
Bessemer soft steel can be bent backwards and forwards hundreds of times 
without a fracture, and are almost as flexible as paper. 
PHOTOGRAPHY. 
W ITH so many claims upon the wall-space of the International Exhi- 
bition, it appears that the Royal Commissioners have not been able 
to place at the disposal of intending photographic exhibitors so large an 
amount of accommodation as will fully satisfy all demands. They have 
devoted, however, no less than three thousand square feet to the exhibi- 
tors in this department ; and we may confidently anticipate that the forth- 
coming display will contain the choicest results, and be characteristic of our 
English operators. M. Claudet, as the exponent of the opinions of a large 
section of our most distinguished artist photographers, has addressed a letter 
to the Council of the London Photographic Society, wherein he advocates the 
policy of organizing, without delay, an independent exhibition for the recep- 
tion of such works as are necessarily excluded from the International building 
at Kensington, but which, if collected, would constitute in themselves a very 
complete and interesting supplementary gallery, likely to possess great attrac- 
tion for a numerous class of visitors to the metropolis during the coming 
season. Independently of M. Claudet’s suggestion, a committee of the 
South London Photographic Society have already announced the terms 
of a mutually advantageous arrangement which they have entered into with 
the Directors of the Crystal Palace Company. If this scheme can be carried 
into effect at Sydenham, it is proposed to devote a large space in the first 
gallery, immediately adjoining the central transept, to the purpose of a 
British and Foreign Photographic Exhibition ; and in recognition of the 
efforts of those who contribute to this collection, it is intended to present to 
each exhibitor a season ticket, available for six months from the period of 
inauguration, which is provisionally fixed for the 15th of May. 
Since the period of the last report, M. Joubert has accomplished much 
towards perfecting his process for transferring photographs to glass and porce- 
lain. Some of the photo-enamels which that gentleman exhibited on a recent 
occasion were unexceptionable as Avorks of art. 
Great progress has lately been made also in the production of transparent 
photographs upon glass slides, suitable for exhibition in the oxy-hydrogen 
lanterns. Mr. England employs a dry-collodion process in Avhich tannin is 
the preservative agent, and prefers the use of a solution of sulphate of iron 
for developing the image. The magnified representations of street-scenes in 
Paris are remarkably true to nature, from their having been the result of 
instantaneous exposure ; and the pictures Avhich Mr. England has taken of 
the Niagara Falls, and other famous illustrations of American scenery, are 
also highly successful, Avhether examined in the stereoscope or projected upon 
a screen. 
