5t*4" PHILOSOPHICAL TRANSACTIONS. [aNNO 1685. 



muscles, and the diaphragm. He subjoins cuts, representing the 4 stomachs 

 of the ruminanlia bisulca, the single stomach of the rabbit, and the oesophagus 

 of an ox. The third book consists of reflections and speculations. 



II. Castorologia d. Jo. Mario, aucta d. Jo. Franco. Aug. V^indel, ld85, Svo. 



N° 177, p. 1249. 



A treatise, wherein is delivered the natural history of the beaver, with an 

 account of the medicinal uses of that peculiar odorate substance, named castor, 

 which is contained in little bags or follicles situated near the anus. 



On the Magnetical Fariation at Nuremberg, in the Year l685. By M. G. C. 

 Eimart, &c. Abridged from the Latin. N° 178, p. 1253. 



In the beginning of August, l685, having taken all possible care to be cer- 

 tain of our meridians, we tried several magnetic needles^ both those old ones 

 we had employed in observing about 5 years before, and many new ones, of a 

 middling length, the longest not above 6 inches, but which were more slender 

 and active ; and, what is strange, we found the declination of the needle not to 

 vary one minute, but exactly agreeing with the former in every meridian, being 

 again just 5° 5' to the west. Whether it has gone farther in the mean time, or 

 its deviation be now retrograde, which might by chance be the case, is not cer- 

 tain ; for I am not willing to assert that, being rather inclined to think it has 

 been stationary at that point, its motion doubtless being circular.* 



On Dr. Papinsnew Water Engine. Br IV. Tenon. N° I78, p. 1254. 



Reading lately in the Transactions a description of the effects of a water 

 engine, invented by Dr. Papin, and propounded as a problem to find out the 

 contrivance, the following thought occurred to my mind. I do not think it is 

 the same with his, nor so good, but such as it is I send you, because variety of 

 fancies gives hints many times to better new inventions. 



In pi. 8, fig. 1, ABDE represents a cylindrical vessel closed on every side, 

 and divided into two rooms or parts by the floor or partition E F. And G L M H 

 is another cylindrical vessel, within the upper room, cemented with its mouth 

 downwards to the floor, and full of water up to the surface I K ; the upper part 

 thereof, G I K H, being full of air. Q O, R P, two pipes open above and below, 



• This doubt has probably been owing to some inaccuracy in the observations, as the variation has 

 certainly been gradually increasing westward in Europe, since about the year \666, and is now near 

 23* west; but whether at present stationary seems to be uncertain,_owing to the want of observations 

 on this curious phenomenon. 



