600 
PROCEEDINGS OF THE SOCIETY. 
binocular Microscope on the Cherubin d’Orleans model, in wbicb lie 
used two Seibert’s objectives. He wanted to see wliat difference there 
would be between the stereoscopic effect produced in this way and that 
obtained by Mr. Wenham’s arrangement. The result was exceedingly- 
pleasing ; he never saw anything so nearly approaching the natural 
beauty of the object as the effect which he obtained by viewing it 
through two objectives in this manner. When the Porro prisms came 
out, he thought that they could be used for the purpose to which they 
were applied in this Microscope. It was, as Mr. Michael had surmised, 
only available for low powers, but extremely beautiful effects could be 
got out of it. 
During the vacation he had stumbled across a delightful old book, 
which was partly devoted to optics, and partly to magic and philosophy. 
He had thought the Porro prism was a new thing, but to his surprise, 
he found it was described in this old book, dated 1702. He had also 
been under the impression that Jordan’s sunshine recorder was some- 
thing which belonged to the 19 th century, but on looking through this 
book, there it was, with a number of ingenious modifications. Telescope 
sights for guns he also thought to be a new invention, but these were 
there too, and not only fitted to guns, but also to cannons. 
Pere Cherubin d’Orleans had in 1671 anticipated the drawing panto- 
graph which Dr. Isaac Roberts described in the ‘ Monthly Microscopical 
Journal,’ vol. viii, page 1, July 1872. 
Cherubin d’Orleans (whose real name was Francois Lassere) was 
the inventor of binocular Microscopes and telescopes, and consequently 
of the opera and field-glasses of the present day. He was a man who 
was greatly in advance of the time in which he lived. In his optical 
book he describes the apparatus, and methods of grinding and polishing 
lenses. 
The President made some remarks on an interesting old Microscope 
which had belonged to Sir David Brewster, and which Mr. C. L. Curties 
had brought down for exhibition. It was provided with six powers, 
amongst which was the original Garnet lens. 
Mr. J. E. Barnard read a paper ‘ On the Application of the Electric 
Arc to Photomicrography,’ in which he described the successful arrange- 
ments devised by himself and Mr. Carver. In illustration of the subject, 
an image of the carbon points with the arc between them was projected 
upon a screen, and the most effective position and distance thereby 
demonstrated. The difference between the action of the continuous and 
the alternating current was also shown in the same manner. Photographs 
of the lamp and its accessories, and photomicrographs taken in the 
manner described, were also shown upon the screen. 
Mr. Yezey said he understood that Mr. Barnard did not claim a 
hand-fed arc lamp as a novelty, because such lamps had been in use for 
some time in lantern work, where it was essential for the source of light 
to be kept central to the condenser. He referred to Mr. Davenport’s 
patent electric lamp and others which had been designed for this pur- 
pose. 
Mr. Barnard said he was quite aware that there were many forms of 
