SCIENTIFIC SUMMARY. 
125 
North-Eastern Photographic Exhibition. — Mr. H. P. Robinson, one of the 
exhibitors and jurors of this exhibition, whose contributions were noticed 
critically in our last, writes denying the truth of our descriptive remarks on 
the jury awards. All the statements we made had been previously and 
repeatedly published in The British Journal of Photography , The Photo- 
graphic Notes, The Photographic News, and The Journal of the Photo- 
graphic Society. We must, therefore, refer him to their pages as a more 
suitable medium for discussing such a subject in. Our business is merely 
that of chronicling historical facts. 
New Lenses. — A very remarkable new photographic lens is about to be 
introduced by the well-known optician Herr Steinheil, of Munich, which he 
calls the Periscopic. It was first described at a seance given by the Academie 
des Sciences of Berlin in July last, and its chief novelty is that of being 
constructed of crown glass only, and yet being, on the authority of the 
continental scientific press, and the statements of reliable authorities, 
perfectly achromatic ! The editor of The Photographic Nevjs, however, 
states that it is non-achromatic ; but as he confessedly speaks from hearsay, 
and adds that he “ looks with interest for more definite information ” than he 
has yet received, we presume he has no other means of testing the truth of 
the assertions made than we ourselves possess. Two symmetrical crown glass 
meniscus lenses, so deeply curved as to resemble, when placed with their 
concave surfaces outside and a little apart, the form of the globe lens, may, 
by the aid of a small stop in the centre of the space between the glasses, 
give images in which the chromatic aberration will be scarcely visible : but it 
will still exist. The use of so small a stop, and the length of exposure it would 
render necessary, would, however, affect the character of the photographs 
produced, and in those taken with this instrument, exhibited at the last 
meeting of the Photographic Society, there is no evidence to warrant us in 
adopting such an idea of Herr Steinheil’s novelty. This new lens is to be 
manufactured by Yoigtlander ; it is very small, is said to be perfectly free 
from distortion, and its angle of view is so great that a lens of sixteen inches 
focus covers a field of thirty-two inches ! The Paris correspondent of the 
British Journal of Photography states, “that the non-completion of the 
French and English patents may cause delay in placing these lenses in the 
market,” and tells us that “ the time of exposure is not more than with the 
ordinary globe lenses.” We presume the new instrument will be considerably 
lower in price than those of the usual construction. 
Another new lens, of which report speaks highly, is termed the Pantoscopic 
lens, first exhibited, we believe, before the Photographic Society of Berlin, 
by Herr Busch. It is a globe lens, with a field of 95°, and it is said to give 
images free from distortion. 
New Photographic Papers. — For years past there have been continual com- 
plaints published with regard to the bad character of the paper supplied for 
photographic purposes, for which reason we are glad to find that within the 
last three months three new papers have been announced. One in Paris by 
M. Loewe, in which the unsatisfactory use of albumen is dispensed with, in 
favour of a new substance so closely resembling it, that chemical analysis 
cannot detect the difference, but which is yet said to be quite free from the 
