riiOCEEDINGS OF THE SOCIETY. 5«>9 



ether, one was approaching a subject which was altogether too large for 

 discussion, because it was a problem whether ether existed at all. If it 

 should be discovered that light had nothing to do with ether, but was 

 merely the manifestation of electrical stress, it would alter their views ; 

 but he thought there were some measurements of a thousand or two 

 years back, astronomical measurements, which led to the belief that the 

 wave-length was not likely to have changed during that, perhaps, com- 

 paratively short period. He thought it was of great importance to be 

 able to get a standard which could easily be reproduced, by physical 

 means instead of by mechanical methods, in case some earthquake should 

 come and destroy the standards, even apart from the question whether 

 the ether might, in the course of a few hundred thousand years, vary in 

 its physical properties. He thought it was now generally recognized that 

 measurements based on wave-lengths were likely to be of great service. 



Mr. Conrad Beck exhibited a New Portable Microscope suggested by 

 Mr. Murray. He said that this instrument had been designed to the 

 suggestions of Mr. James Murray, the well-known explorer, who was 

 anxious to have a Microscope extremely small and portable, and which 

 could be used in the field. Being away from the comforts of civiliza- 

 tion, in tropical forests, he would be debarred from the luxury of chairs 

 and tables, and the Microscope was therefore so designed that it had 

 one leg, which could be strapped to a walking-stick, which is then 

 driven into the ground, and the observer could sit with the stick pro- 

 jecting from the ground between his legs, and the Microscope could be 

 inclined by means of the usual joint to a convenient position. The in- 

 strument was on the model of the Star Microscope, with an aluminium 

 stage, and all the superfluous metal removed everywhere to make it 

 extra light. It had a sliding coarse-adjustment, a micrometer-screw 

 fine-adjustment, and a small substage condenser, with iris-diaphragm. 

 It was provided with two loose legs, which screwed into the single 

 leg-base, making it into a tripod for use on a table in the usual way, 

 when such a support was available on the return from an expedition. 

 For the study of pond-life on the spot this instrument was specially 

 desirable, as the naturalist on the walking-stick-stand principle might 

 spend many profitable hours in pleasant weather in conducting his 

 microscopical examination at the side of the pond, or on the country- 

 side in the open air. 



Mr. Murray remarked that as the journey he was about to undertake 

 had to be made without the assistance of carriers, it became important to 

 reduce the weight to the utmost, because every ounce put into instruments 

 to be carried must be deducted from the amount of food which could be 

 carried. Therefore, remembering his previous experience with the Star 

 Microscope on his journeys, he asked Mr. Beck if he could improve upon 

 that instrument in the matter of weight. The present Microscope was 

 the result. It was true that the necessity for unscrewing the legs of the 

 tripod introduced a structural weakness, but the instrument was intended 

 to be primarily used on a walking stick. Its use in the ordinary way. on 

 a table, was a secondary matter. It was not anticipated that one would 

 be able, as Mr. Beck had said, to sit comfortably and work with the 

 Microscope ; that was usually impossible in the Amazonian forest. It was 



