138 



THE POPULAR SCIENCE MONTHLY. 



frequently fail at the critical moment, caus- 

 ing loss of life or damage to property. Re- 

 cently a system of protection has been per- 

 fected and is now being introduced, which, 

 the promoters claim, secures perfect safety, 

 and the trials made in this and other cities 

 seem to amply confirm the claim. It con- 

 sists in making the descending carriage act 

 as a plunger to compress the air in the shaft 

 below it, so as to form a cushion which re- 

 tards and gradually overcomes its motion. 

 The change in the ordinary construction of 

 the elevator to secure this action is very 

 slight, and can readily be applied to one al- 

 ready put up. The shaft is made to fit the 

 elevator carriage closely, through the first 

 three or four feet of the lower portion, and 

 then gradually widens to the full size. This 

 funnel-shaped portion extends from fifteen 

 to twenty feet above the contracted base, 

 depending upon the size and height of the 

 elevator. A stiff rubber flange around the 

 lower edge of the carriage leaves a space 

 for the escape of the air in the contracted 

 portion of not more than one fourth of an 

 inch wide. The straight part of the shaft 

 above the funnel is of a size to leave a 

 space of six to eight inches all around the 

 carriage. With such a constructed shaft, 

 the carriage, when it begins to fall, readily 

 presses the air from beneath it up the sides 

 of the shaft. As it gains in velocity, greater 

 resistance is offered by the air, and, as it de- 

 scends through the funnel portion, this is 

 rapidly increased by the narrowing of the air 

 outlet. When the contracted base portion 

 is reached, the confined air has only a 

 narrow outlet, and the resistance it offers 

 is consequently very great. The air ar- 

 rests the motion of the carriage so gradually 

 that there is very little shock. In one of the 

 trials in this city where the fall was seventy- 

 five feet, eggs and delicate glassware placed 

 on the floor of the car were unbroken. A 

 great number of trials have been made, and 

 many persons have gone down in the falling 

 cars without injury. With the shaft prop- 

 erly and strongly built in the lower portion 

 where the strain comes, this apparatus seems 

 to offer no chance of failure. 



Types of Pottery. Professor E. S. Morse 

 read an interesting paper on this subject at 

 the last meeting of the American Associa- 



tion. The earlier types belonging to the 

 shell-heaps of Japan were described and 

 illustrated by specimens from each of the 

 deposits examined by Mr. Morse and his 

 special students. The pottery of Yezo was 

 nearly all cord-marked, while the shell-heap 

 pottery of the middle of Japan had a much 

 less proportion cord-marked. In the south- 

 ern portions of Japan, at Higo, cord-marked 

 pottery was extremely rare. lie remarked 

 on the extreme diversity in the shape and 

 ornamentation of the pottery in different 

 places in Japan the pottery of Yezo re- 

 sembling the pottery of the northern Uni- 

 ted States, and the pottery from the central 

 portions of Japan resembling that found in 

 Porto Rico and Jamaica. He also spoke of 

 the hard, blue pottery supposed to be Corean, 

 and associated with it a red pottery which 

 might have been made by the same people. 

 This was lathe-turned. Other forms were 

 mentioned and illustrated by examples. 



The Fiftieth Meeting of the British As- 

 sociation. No remarkable discoveries were 

 brought forward at the recent meeting of 

 the British Association for the Advancement 

 of Science, but the addresses and papers in 

 the various sections showed a steady ad- 

 vance in scientific work. Professor A. C. 

 Ramsay, the new President, chose for the 

 subject of his inaugural address the doctrine 

 of uniformity, under the title of " The Re- 

 currence of Certain Phenomena in Geologi- 

 cal Time." There has recently been a dis- 

 position in certain quarters to question the 

 truth of the doctrine in the extended appli- 

 cation made by most geologists. The ques- 

 tioners admit that geologic changes in times 

 past were produced by the same forces now 

 in operation, but deny that they were of the 

 same degree. The uniformity and cataclys- 

 mic theories seem to them to both contain 

 truth. Professor Ramsay reafiirms the uni- 

 formity doctrine in the broadest and most 

 general manner, and very ably defends his 

 position. One of the most valuable if not 

 the most important address of the meeting 

 was that of Professor W. G. Adams, before 

 the Section of Mathematics and Physics, re- 

 viewing recent work in the domain of molec- 

 ular physics. His statement of the molec- 

 ular condition of the three forms of matter 

 solid, liquid, and gaseous was the clear- 



