42 



PHILOSOPHICAL TRANSACTIONS. 



[anno 1713, 



to observe them both at once. Yet I believe the following tables may be de- 

 pended on, to be as true as the nature of such an experiment is capable of. I 

 have formerly given a particular account of the manner of making this experi- 

 ment, in the Phil. Trans. N° 334. These tables are calculated from the touch- 

 ing ends of the planes; and it is to be observed, that in the table where the 

 planes were opened only to an angle of lO', that I could not come nearer than 

 4 inches of the touching ends in my observations: but so far as I could go, 

 seems to be much in the same proportion (as I have often observed in the 

 course of these experiments) with the table where the planes were opened to 

 an angle of 18'. 



The Planes opened to 

 an Angle of \ 8'. 



A. , 



Oittaocet in 

 laches from 

 the touch- 

 ing Ends. 



The Planes opened to 



an Angle of 18'. 

 /v . 



The Planes opened to 

 an Angle of lO'. 



Angle of 

 Elevation. 



Angle of 

 Elevation. 



16^. 

 124- 



45' 

 55 



05 

 20 

 30 

 40 



8| 2 00 



74 



30 

 20 

 25 



Distances in 

 Inches from 

 the touch- 

 ing Ends. 



4^ 6° 00' 



4 7 23 



3\ 8 40 



3^ .9 25 



3^ 10 30 



3 12 40 



2| 15 00 



24 18 50 



2^ 23 25 



2 30 00 



Distances in 

 Inches from 

 the touch- 

 ing End. 



Angle of 

 Elevation. 



i6i 

 144 



124 



9i 



^30' 



50 



10 



40 



10 



30 



84. 4 00 



7i 5 05 



6^ 7 40 



54 10 50 



4^ 14 00 



4 1800 



Inscriptio Tarraconensis : cum Commentario Guil. Mtcsgrave, M, D. Coll. Med. 

 et Societ. Reg. Lond. Socii. N° 337, art. 15, p. 157. 



Some further Microscopical Observations on the Animalcula found on Ducktveed, 

 ^c. By Mr. Leuwenhoeck. N° 337, art. 16, p. 160. 



In N° 295*, I took notice of the surprising figure of an animalculum, fixed 

 in a little scabbard or sheath, fastened to some of the small green weeds, found 

 in ditches of water. And as often as I have viewed these animalcula, and 

 showed them to others, we could not satisfy ourselves with looking on such 

 surprising objects ; and the more, because we could not conceive how so strange 

 a motion, as they all had, could be performed; as also what should be the use 

 of such a motion. For when we observe other animals, that are endued with 



* Page 175, vol. V. of this Abridgmeot. 



