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HARDWICKE'S SCIENCE-GO SSIP. 



[April 1, 1869. 



one is aware a drawing looks very objectionable 

 when finished upon tracing-paper : further, there is 

 a considerable loss of light in passing through the 

 medium or paper. What we require is, in being- 

 able to draw upon a piece of card or Bristol board. 

 To this cud I have made many experiments, and the 

 most successful and (I may be pardoned for adding) 

 very satisfactory aud simple means I beg to place 

 before your readers. 



I enclose a rough sketch to simplify the 

 description. A is a ring containing two mirrors, 



milled head B, aud clamp it by the tightening screw. 

 By using the flat mirror you obtain brightly illumin- 

 ated and full of detail, ou your card or paper a view 

 the same size as presented by the microscope ; but 

 by using the concave mirror you obtain a much 

 larger picture, without, of course, altering your ob- 

 jectives, and by raising your instrument a little (of 

 course altering the light at the same time) you 

 rapidly enlarge your diagram. 



I hope this little appliance may be of some service 

 in that most difficult of all drawing (microscopical) ; 



Fig. 57. Drawing Apparatus. 



one a concave of about G-inch focus, the other a flat 

 one. B is a small milled head to regulate the angle 

 of rays : on the opposite centre there is a little 

 larger milled nut, whicli clamps the mirror tight to 

 the arms C. D is an ordinary clip, lined with cloth 

 to prevent scratching the lacquer, with a milled 

 bead E, to clip it tight to the body of microscope F. 

 G represents the card or paper for drawing upon. 

 To use this apparatus proceed thus : — 1st. Place the 

 microscope in a horizontal position ; direct the rays 

 of light from a Bockctt or other lamp, carefully ex- 

 cluding all rays not concentrated upon the mirror, 

 or, in other words, concentrate all the rays you can 

 from your lamp on to the concave reflector, so as to 

 illuminate as powerfully as you can. 2nd. Take 

 out the eyepiece and slip the clip Don to the body; 

 do not tighten the clamp E until the eyepiece is in, 

 as it will help to support the pressure exerted on 

 the tube, as many instruments have rather thin 

 bodies. 3rd. Set the angle of the mirror by the 



aud should any of your numerous readers require 

 further instruction, it will be cheerfully given by 

 your constant subscriber, 



W. SCANTLEBURY. 



Microspores.— I have found the macrospores 

 spoken of by E. W. Binney at the meeting of the 

 Manchester Philosophical Society, January 26th, 

 1869, in shale from above the Low Main scam of 

 coal at Cramlington, Northumberland. They are 

 flattened and disc-like in appearance, and in one or 

 two instances the triangular markings arc seen the 

 same as in the microspores of Lcpidostrobus. ]na 

 section of Lepidostrobus now in my cabinet the tri- 

 angular markings on the microspores are well shown 

 in some, and in others the spores are seen breaking 

 up at the triangular marking into sporules. Whe- 

 ther the macrospores break up in the same way or 

 not I think has yet to be determined.— John Butter- 

 worth. 



