Xo."50210. 



Heliostats. 



33 



50 200. 1 : 7. 



03 



3 



;- 



0> 



O 



I 



a 



S 

 a> 



.S3 

 O 



50 205 A. 1 : 8. 



50 205 B. 1:8. 



50 208. 1:5. 



50.202. Small Cupboard for Chemicals, for storing the reagents necessary for hand use . 



| s. d. 



2. 8. 







x 



ee 



A wall cupboard for suspending, made of deal, stained and varnished, with glazed double doors; 

 60 cm wide, 80 cm high, 15 cm deep, with 4 adjustable shelves of crude glass with polished edge. 

 The wood parts are coated a light-blue oil-colour inside. 



Wall Heliostats, Figs. 50,205 A and B. 



For walls up to 54 66 



List No. 50,205 50.206 



Price 4. 0. 4. 15. 



78 cm thick 

 50,207 

 5. 10. 



The brass heliostat tubes can be slid without friction in a zinc tube (F i g. A), fitted in the wall, 

 and can be easily turned about in the latter. When the heliostat is not in use the opening in the wall 

 is closed by a cylindrical closing plate (Fig. B). If the Physics Room is inconveniently situated, a 

 number of openings in different directions can be made so as always to have sun-light. The heliostat 

 is arranged for horizontal rotation by hand. The mirror is foeussed by means of a gut cord stretched 

 by a spring, and a knob. The mirror holder has on one side a good silvered glass mirror, and on 

 the other side a black mirror for diffraction experiments. The following are included with the helio- 

 stats: an attachment, with adjustable slit, and an attachment with diaphragm disc with round 

 holes of varying size and with serpentine slit. 



An additional attachment with adjustable slit having micrometer screw and divided drum involves 

 an increase in price of about ; 0. 10. 



Wall Heliostat, Figure, horizontal motion by rack and pinion. Mirror motion by end- 

 less .screw. With 1 silvered and 1 black glass mirror; also with 1 slit attachment with 

 micrometer screw and divided drum, and 1 diaphragm annex, all brass: arrangement 

 of tube and construction as Xos. 50,205 50,207, arranged for use with the solar 



microscope. 



For wall to 



List Xo. 



Price 



54 



50,208 

 6. 10. 



66 



50,209 

 7.5.0 



78 cm thick 

 50,210 

 8.0.0 



The special annex with serpentine slit shown in the figure, is not supplied with the heliostat : 

 the diaphragm attachment, however, is provided with such a slit" (cf. the diaphragm annex in Fig. 50.-214). 



A solar microscope can be directly attached and does not turn along with the mirror when the 

 latter is being focussed. 



For Large Chemical Cupboards, see pp. 53 and 54. 



Cl. 3193. 38, 



39. 41. 



