xviii Trans. Acad. Sci. of St. Louis. 



vested funds to the amount of $6,500.00, and a balance of 

 $555.25 carried forward to the year 1902.* 



A letter from Mrs . William Bouton was read , offering on behalf 

 of herself and other contributors to a purchase fund, to present 

 to the Academy a collection of 633 butterflies mounted on Den- 

 ton tablets, and the containing cases, on condition that the 

 collection be held as an educational exhibit for the benefit of 

 the public, and in all feasible ways kept open to public in- 

 spection, and the following resolution was adopted : — 



Besolved, That The Academy of Science of St. Louis gratefully accepts 

 the gift as proposed by Mrs. Bouton, and agrees to hold the collection 

 as an educational exhibit for the benefit of the public, and In all feasible 

 ways to keep it open to public inspection. 



The following papers were presented by title : — 



K. K. Mackenzie and B. F. Bush, new species of plants 

 from Missouri. 



B. F. Bush, Ee vision of the North American species of 

 Triodia. 



Professor A. S. Chessin exhibited a gyroscope and ex- 

 plained how an accurately constructed and rapidly rotated 

 gyroscope might be made to indicate the position of the 

 meridian plane, the direction of the polar axis of the earth 

 and the latitude of the place of observation, thus serving the 

 purpose of the mariner's compass, but more accurately 

 because of the fact that the compass indicates the magnetic 

 and not the true pole. The following formulae pertaining to 

 the subject were furnished : — 



^-'"V a 0,12 cos X ^^-'^\ ci^ — 



where 2' and T^ are the durations of a complete oscillation 

 of the gyroscope when its axis is made to remain in the hori- 

 zontal and the meridian planes respectively ; co and £1 the 

 angular velocities of rotation of the earth and the gyroscope 

 respectively; A, Ai, A2 and (7, (7i, (72 the equatorial and 

 the axial moments of inertia of the gyroscope and the 



