4l6 PHILOSOPHICAL TKANSACTIONS. [aNNO 1687. 



it is full, one may fish in it. In winter time it will be so firmly frozen as to 

 bear all sorts of carriages, which is a great convenience to the people to fetch 

 •their wood and other necessaries. Lastly, at the time when the water goes 

 away, it yields great abundance of fish, as beforesaid. And that which is most 

 wonderful is, that all this comes to pass in the same place, and the same year, 

 viz. if the lake be early dry, and it fill not too soon ; but it is to be noted, that 

 the hay does not grow, nor is the millet sown all over the lake, but only in the 

 more fertile places. 



There are only three sorts of fish taken in this lake, which are very well 

 tasted. They are the mustela fluviatilis or eel-pout, some of them weighing 

 2 or 3 lb. ; tench, some of them weighing 6 or 7 lb. ; and, thirdly, pikes, in very 

 great plenty, of 10, 20, 30, and some of 40 lb. weight; in the bellies of these 

 it is common to find whole ducks. Crabs are found no where but in the pits 

 Kamine and Sueinskajamma. 



The cause or rather modus of all these wonderful phaenomena in the lake of 

 Zirknitz, is probably as follows. There is under the bottom of the lake another 

 subterraneous one, with which it communicates by the several holes described ; 

 there are also some lakes under the mountain Javornik, whose surface is higher 

 than that of the lake of Zirknitz. This upper lake is perhaps fed by some of 

 those many rivers, which in this country bury themselves under ground, and 

 has a passage sufficient to carry the waters they bring unto it ; but when it 

 rains, especially in thunder showers, which are the most hasty, the water is pre- 

 cipitated with great violence down the steep valleys, in which are the channels of 

 these rivulets ; so that the water in this lake, being increased by the sudden 

 coming in of the rains faster than it can empty, swells presently ; and finding 

 several holes or caverns in the mountain higher than its ordinary surface, it runs 

 over by them, both into the subterraneous lake under that of Zirknitz, into 

 which the water comes up by the several holes or pits in the bottom of it, as 

 likewise by visible passages above ground. 



That some of these passages bring fish, some ducks and fish, others only 

 water, seems to depend on the position of the inward mouths of these subter- 

 raneous channels : for if they be so constituted as to draw off the water from 

 the surface of the upper lake, on which the ducks swim, they must needs be 

 drawn away by the stream into these caverns, and come out with the water ; but 

 if the channels open into the upper lake under the surface of the water, and 

 from thence ascend obliquely for some space before they come to descend ; then 

 the water they carry is drawn from below the surface, and consequently can 

 bring with it no ducks, but only fish. Those pits which yield only water may 

 well be supposed to be fed by passages too narrow lo let the fish pass, though 



