CONTENTS OF NUMBER II. ARTICLE. PAGE. 81 VI. On some points in American Geology. By T. VII.-Correspondence of Jochim Barrande, Sir William Logan and James Hall on the Taconic System. 106 VIII-Catalogue of Plants collected in the Counties of Argenteuil and Ottawa, in 1858. By W. S. M. D'Urban..... 120 IX.-Notes on the Geology of Murray Bay-Lower St. Reviews and Notices of Books. The limits of exact Science as applied to History. By The life of William Scoresby. By his Nephew, R. E. Manual of Modern Geography, Physical and Political. By 151 152 the Rev. Alex. Mackay, A.M., F.R.G.S......... 153 Transactians of the Philosophical Institute of Victoria.... 155 All business communications to be addressed, prepaid, to the Publishers. Articles and communications for publication in the Journal may be addressed to the Editors, care of the Pub lishers. Authors of original articles can have 12 copies of them by giving timely notice; it is too late when the forms are broken up. The next number of this Journal will be published in June 1861. NEW Achromatic Stereoscope. Price in Walnut Wood, Do. Mahogany do., $23.00 $21.00 Stereoscopic Phototographs of the Moon on Glass, from negatives taken by Warren De la Rue, Esq., F. R. S., $6.50 Extract from the "Athenaeum," Aug. 28, 1858, page 269. "The adoption by Mr. CHAPPUIS of the principle of the daylight reflector to the stereoscope was noticed by us in the Athenæum for Nov. 7th, 1857. We there made some suggestions for further improvements, with a recommendation to Mr. CHAPPUIS to try them.' That gentleman has not done so; but Messrs. SMITH & BECK have not only carried out, they have gone beyond our suggestions,-and from a toy the stereoscope has progressed to an object belonging to science. A few words will enable our readers to understand the improvements that have been made. in this justly popular instrument. 1st. By the introduction of achromatic lenses the optical part is greatly improved, thereby increasing the definition and correcting the colour which single lenses invariably show on the margin of the objects. These errors in the unachromatic stereoscope frequently destroy the delicacy of the image altogether.-2nd. By the application of lenses of such a focal length, and placed at such a distance apart as that all shall see without fatigue, which is not the case with those hitherto contrived. But with these improvements in the optical part of the instrument arose the need of greater delicacy in the mechanical contrivances for observing to the best advantage; this led-3rd. To an arrangement whereby any one having the sight of both eyes could see the effect.-4th. A thoroughly steady and substantial stand adapted for a person seated at a table, and allowing of any alteration of position. 5th. A method for holding the slides so that they can be placed and replaced easily and without danger.-6th. Means have been adopted for varying the illumination at pleasure, causing a great variety of very beautiful effects of light and shade, from the cool tints of moonlight to the ruddy glow of the morning sun. And, lastly, a compact case to keep the whole from dust, injury, or exposure. The result is a perfection beyond which it is hardly possible to carry the stereoscope. This perfection is admirably exhibited in the stereoscopic views of the Moon, taken on glass by Mr. HOWLETT, from the negatives obtained by Mr. WARREN DE LA RUE with his equatoreal reflecting telescope of 13 inches aperture and 10 feet focal length. The stereoscopic effect is obtained by combining two views of the moon, taken at different epochs nearly in the same phase, but when the disc is in two different conditions of libration." SMITH, BECK & BECK'S IMPROVED MICROSCOPES. Price of the Educational Microscope, .... from.. ..$65.00 and $96.00 $96.00 to $200.00 Apparatus, &c., Instruments used in preparing and materials in mounting Microscopic objects, or any other article of their manufacture can be supplied by FRANCIS CUNDILL, AGENT, 6 Commercial Chambers, St. Sacrament Street, MONTREAL Catalogues forwarded. ARTICLE X.-On the Pre-carboniferous Flora of New Brunswick, Maine, and Eastern Canada. By J. W. Dawson, LL.D., F.G.S., &c. (Read before the Natural History Society.) The known flora of the rocks older than the Carboniferous system, has until recently been very scanty, and is still not very extensive. In Goeppert's recent memoir on the flora of the Silurian, Devonian, and Lower Carboniferous rocks,* he enumerates 20 species as Silurian, but these are all admitted to be Algae, and several of them are remains claimed by the zoologists as zoophytes, or trails of worms and mollusks. In the Lower Devonian he knows but 6 species, five of which are Algae, and the remaining one a Sigillaria. In the middle Devonian he gives but one species, a land plant of the genus Sagenaria. In the upper Devonian the number rises to 57, of which all but 7 are terrestrial plants, representing a large number of the genera occurring ia the succeeding Carboniferous system. Goeppert does not include in his enumeration the plants from the Devonian of Gaspé, described by the author in 1859,† having seen only an abstract of the paper at the time of writing Jena, 1860. + Journal of Geological Society of London, also Canadian Naturalist. CAN. NAT. VOL. VI. No. 3. 1 |