KNOWLEDGE & SCIENTIFIC NEWS. 



[August 1906. 



di\idcd with a metre ihIc, each 5 minutes of the circle 

 equalling 2 mm. The result will be a convenient circle 

 having- a diameter of about 7 inches. The engraving is 

 easily done with a pointed penknife and ruler, and the 

 markings blackened with solution of antimony chloride 

 (butter of antimony). The figures are preferably in 

 plain English numerals, these being more easily read 

 than Roman. The numbering should be anti-clockwise, 

 from right to left, as it will be the circle that rotates. 



Having turned this to a true circle and soldered the 

 ends, a strip is soldered across, forming a diameter, 

 and the centre of this is soldered to the end of the fork 

 stem as shown. 



The declination circle is made from a brass strip 

 720 mm. long, each degree equalling 2 mm. If the 

 cogged wheel of the bicycle is 9 ins. in diameter, a 

 usual size, it will be found that with a little filing of the 

 cogs the strip will exactly go round, and may be fixed in 

 position by soldering at each cog. 



Verniers are fitted to both circles as shown; pieces of 

 brass 18 mm. long are divided into 10 equal parts; the 

 R.A. vernier will thus read to 30 sees, and the declina- 

 tion vernier to 6 mins. Thumb-screws are made to 

 clamp in R.A. and declination. 



A slow motion in R.A. is a great advantage, and a 

 simple device is to put a cogged wheel (from a clock or 

 similar contrivance) around the handle-bar tube; this 

 can be driven by a smaller cogged wheel fixed to the 

 head; a handle is made by soldering a brass rod to a 

 spiral brake spring, and this to the small wheel. As 

 the telescope rotates on ball bearings comparatively 

 little strength in this slow motion is needed, and the 

 spiral spring, while allowing the handle to be used in 

 any position, does not " give " unduly. 



Finally the main support can be let through a 

 mahogany block on a tripod stand, and adjusted to any 

 height, or permanently fixed by cementing it into a 

 large drain-pipe set on a concrete base. Or it can be 

 fitted to a more elaborate stand with levelling screws 

 and artistic masonrv. 



With regard to the performance of the instrument, 

 that will depend on the care w-ith which it is made and 

 adjusted; there is no reason w'hy any star should not be 

 in the field of view with a low power eyepiece, pro- 

 \ ided crdculations are made from some book, such as 

 the "Science Year-Book," which should be found in 

 every astronomer's library. 



As to the cost, an old bicycle can be bought for a few 

 shillings; doing all the work but brazing and thread 

 cutting, the cost to the writer was under half-a-guinea. 



The adjustment will probably take some time, and 

 difficulties will be surely encountered, but by the time 

 the amateur has overcome these he w ill have a very fair 

 knowledge of the " Motion of the Heavens." 



.Attention is directed to the growth of camphorisni, or the 

 habitual use of camphor internally, among the Slovaks of 

 Upper Hungary, by Dr. Aba Sztankay, in Honte Lapok, a 

 Hungarian political journal. Dr. Sztankay has kept an 

 eye on the camphor-consumers for the past fourteen years, 

 asking- each purchaser of the drug to what use he was 

 tjoinfT to put it, and he does not think he exaggerates when 

 he states that fully 25 per cent, of the whole amount of the 

 drug sold is used by the camphor-eaters. That the esti- 

 mate of the quantity of the gum used in this manner must 

 be very consideiably increased, is shown by the fact that 

 grocers and other dealers, beside apothecaries and drug- 

 gists, handle the article. The Slovaks of the region ob- 

 served by the author are subject to frequent attacks of 

 epilepsy, and this he thinks stands in some relation to the 

 habit alluded to, an opinion that is fortified by the fact 

 which he was enabled to verify, that the administration of 

 camphor was followed by epileptoid convulsions. 



Studies in Cohesion. 



Hv Dr. .\liked Gk.\den\\ itz. 



The recent work of l^rofessor St. L.educ, of Nantes, 

 constitutes a considerable advance towards an explana- 

 tion of certain phenomena characteristic of the life of 

 cells, that is, of the constituents of all vegetable and 

 anim:d organisms. Though the enigma of the origin 

 of life is hereby in no way solved (nor can a real 

 solution be expected from a continuation of these re- 

 searches), the mechanism of the phenomena h;Ls been 

 explained to a certain extent. The important part 

 played by diffusion in connection with all life phe- 

 nomena of cells has been more especially ascer- 

 tained, showing the possibility of accounting for the 

 life of living matter, at least as to its external aspect, 

 from a purely physical point of view. These results 

 have recently been completed by experiments showing 

 the no less important part to be ascribed to the force of 

 cohesion. In fact, many phenomena which formerly 

 did not allow of any exphmation may now be readily 

 accounted for on physical laws. 



By inserting drops of a solution in a differently con- 

 centrated solution of the same substance, L>educ has 

 already, a few years ago, constituted artificial cells, the 

 diffusion of the liquid resulting in structures which were 

 entirely analogous in their behaviour to natural cells, 

 and which were exclusively controlled by the laws of 

 diffusion. Now these liquid structures, so far from re- 

 maining unaltered, were recently found to undergo a 

 transformation which was not to be explained by the 

 laws of diffusion. In fact, the structures then produced 

 were wholly independent of the distribution of osmotical 

 pressure. If the evolution of the structure be allowed 

 to continue, motions just opposite to those originally 

 produced under the influence of diffusion would be ob- 

 served, although the direction of forces remained un- 

 altered. 



If a solution of potassium nitrate be spread out 

 on a glass plate and drops of the same solution, but of 

 smaller concentration, coloured with Chinese ink, Ise 

 introduced in the former, these drops, owing to th« 

 differences in pressure, will be found to diffuse and to 

 result in the liquid structure represented in Fig. 1. 



