XXXVl CONTENTS. 



PAGR 



Nactiet's, Collin's's, & " Box" Portable Microscopes (lugs. 137-40) .. Part 4 700 



PPAFF'ii (F.) 3Iicro(jonioineter {Fi'/s. lAl and li2) „ 702 



DovvhE-DnvM Microscope (Fig. liS) „ 703 



Tiieiler's (M. & Sons) " Universal (Achromatic) Pocket Microscope " 



(Fig.lU) „ 704 



ToLMAN, H. L., & M. D. EwELL — Eye-piece Micrometers „ 704 



BoECKEU's Holder for Analysing Prism and Goniometer (Figs. 145 and 



14G) „ 705 



GuxDLACH, E. — " An Improvement in Objectives " „ 705 



WAhES^W.— Care aad Use of Objectives „ 708 



Griffith's (E. H.) 3fcchanical Finger Objective (Fig. HI) „ 709 



Hunt, G. — Right-angled Prism instead of a Plane Mirror „ 709 



Ze^tmayfm's Abbe Condenser (Fig. US) „ 710 



TbVLKR's (A.) Illuminating Apparattis (Figs. Ud-15l) „ 710 



Bausch & LoMB Optical Company's " Universal Accessory'' (Figs. 152 



one? 153) „ 713 



Nelson, E. M., & A. C. Mallet — Illumination (Figs. 154-170) .. .. „ 713 



'H.AViKVSfC-i (R.) Observatory Trough „ 719 



'PiMSG?,nF\si'i(^.) Gas Chambers (Figs. Ill and \12) „ 720 



BEm', J.— Test for the Hand-Lens „ 720 



Aperture Pu2zfe (f'iV/s. 173-175) „ 721 



Govi — Discovery of Pseudoscopy „ 722 



Carpenter, W. B. — Focal Depth with the Binocular „ 726 



M'Allister — Slide showing Path of Electric Spark „ 727 



Schoolroom, Microscope in the „ 728 



He^y's (J.) Twin Microscope (Fig. ISO) Part 5 854 



Klein's (C.) Mineralogical and Petrological Microscope (Figs. 181-183) „ 856 



liE\cwE,ViT:'&(G.) Mineralogical-Geological Microscope (Fig. \Si) .. .. „ 858 



Watson- Wale Mcrosco/je (%. 185) „ 8G0 



Schieck's Microscope with Screw Stage -Micrometer (Fig. 186) . . . . „ 8G1 



Hart, C. P. — Microtome-Microscope „ 861 



DvBOSCQ'a (T. & A.) Projection Microscope ., 861 



"TwTs" Simple Microscope (Fig. 187) „ 862 



Laurent's (L.) Apparatus for Registering the Curvature and Refraction 



of Lenses (Figs. 1S8 and 189) „ 863 



Gundlach's Improved Objectives „ 863 



Stodder, J. C. — Series of Objectives „ 863 



Nelson, E. M. — Right-angled Prisin instead of a Plane Mirror .. .. „ 864 

 Heurck, H. tan — Helot- Trouve Apparatus for Electrical Illumination 



(AV/s. 190-192) „ 864 



D'Arsonval, Malassez, & Henocque — Illumination for Projection 



Microscopes „ 806 



VoRCE, C. M. — Lantern Transparencies „ 866 



MiCRO^coviCA-L Electrical Apparatus (Figs. \93-201) „ 867 



Kegnard, P. — Apparatus for watching the Phenomena that aniinals 



subjected to great pressure present (Figs. 208 and 209) .. .. „ 877 

 Westien's (H.) Apparatus for Comparing symmetrical parts of the Webs 



of the right and left Feet of a Frog (Fig. 210) ,-: , 879 



Sollas, W. J. — Apparatus for Determining the Specific Gravity of 



Minute Objects under the Microscope (Figs. 2\\ and 2\2) 879 



