1898.] MICROSCOPICAL JOURIS^AL. 161 



for microscopic photog-raphy and a limited number of 

 microscopes for students. But each was requested to 

 bring- his own dissecting- and compound microscope. The 

 fee was $20 for the basic course of instruction. ' Students 

 not provided with compound microscopes were charged 

 $5 for the use of one. Board and rooms cost about $1 per 

 day. Mrs. Gertrude Grotty Davenport was instructor in 

 microscopic methods. 



Shameful. — One of our best friends who lives at Elgin, 

 111., says that there are about forty physicians there and 

 that not one of them knows enough about a microscope to 

 be able to resolve a diatom. It would be a dangerous pro- 

 ceeding to let anyone of them manipulate a first-class 

 homogeneous objective. 



SCiENCE-GOSSIP. 



The Smallest "Watch. — The diameter of this is less 

 than half an inch. The exact measurement is 10>^ milli- 

 metres, or .4137 inch. Its thickness is 3 millimetres, or 

 .1182 inch, being but little more than a tenth of an inch. 

 The length of the minute hand is 2 4-10 millemetres, or 

 .09456 inch. That of the hour hand is 1 3-10 millimetres, 

 or .05122 incTi. The entire works of the tiny watch com- 

 prise ninety-five individual pieces, and its exact weig-ht is 

 14.3499 grains, or, according to the metric system, 93 cen- 

 tigrammes-less than a single gram ! After having been 

 wound up with the diminutive key the watcli will run for 

 twenty-eight hours. The mainspring when riin down has 

 a circumference of .13396 inch. Its weight is 38 milli- 

 grammes, or .5902 grain. The weight of the four main 

 wheels, with their springs, is 42 milligrammes, or .6468 

 grain. There are thirteen cogs on the little cylinder 

 wheel, which has a circumference of 2 millimetres, or 

 .0788 inch, and weighs .75 milligramme, or .01155 grain. 

 The balance has a circumference of 3.57 millimetres, or 

 .140658 inch. In one hour it completes 18,152 revolutions, 

 travelling a distance of 9,842 feet 6 inches. The most 



