114 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



between 20° and 60° is obtainable. The variations are not greater tban 

 1/5 to 1/10 of a degree. The temperature of the object under examina- 

 tion is about 2° lower than that indicated by the thermometer in the 

 stage. 



U-shaped Foot.* — Under the title " The U-shaped Foot is clumsy," 

 Mr. W. J. Beall, of Michigan Agricultural College, expresses his opinion 

 of the horse-shoe or Continental form of Microscope foot. Nineteen 

 years ago he selected one or more instruments of some fifteen kinds of 

 stands in order that visitors, his students, and himself, might have a 

 variety for comparison. Since that time he has added other styles to 

 the number. Fig. 9 represents the shape of the horseshoe foot ; fig. 10, 

 the same in section as made of solid metal. Fig. 11 represents on the 

 same scale the shape of the foot of another instrument used for nearly 



Fig. 9. 



Fig. 11. 



r- 



^ 



Fig.' 10. 



Fig. 12. 



twenty years past; and fig. 12 gives a section of the same, the dotted 

 lines indicating the depth of the hollow from the lower side. The first 

 instrument mentioned is 30 cm. high, and weighs six pounds ; the 

 second one is 28^ cm. high and weighs a trifle over four pounds. If the 

 first be placed on a table the least bit curved or uneven, the foot stands 

 on three out of four points and rocks easily ; while number two stands 

 firmly on the table no matter what may be the condition of its surface. 

 When placed side by side near each other, erect or inclined 20° to 30°, 

 and a string is tied to the top, joining the two, and the feet are placed 

 apart, the heavier instrument ti|js over before stirring the other one 

 from its position. The author's opinion, which is strongly opposed to 

 the Continental pattern, is best given verbatim ac litteratim. " True, the 

 narrow base can be pressed into a smaller box than the other, but on the 

 table there is room enough for a broader base. For utility and for 

 beauty, it seems to me the horseshoe foot has scarcely a thing to com- 



* Jnuin. App. Micr., 1S99, pp. 623-4 (4 figs.). 



