378 MAN OF SCIENCE. 



gravel which the matter had not reached. And then it 

 again fell. There is another cave among the rocks of 

 Cromarty that indicates similar changes. 



' I saw on the walls and roof of the cave appear- 

 ances that used at one time greatly to puzzle me. The 

 commoner stalactites drop straight down like the stalks 

 of tobacco pipes, or slant along the walls. Every drop 

 that forms them obeys the gravitatory law. But here 

 and there we find a drop-formed stalk in which this law 

 does not seem to have been obeyed. Some of them 

 curve up at the ends and form hooks, from one of which 

 I suspended my watch, and some of them curve round 

 so as to form loops, both ends joining to the roof. 

 How account for the formation of these? Did water 

 lose its weight in some wonderful age of the world and 

 set itself to drop upwards ? The solution of the diffi- 

 culty when at length discovered proved simple enough. 

 There is a small spider that takes refuge in the colder 

 months in these darker recesses, and forms as it passes 

 along the sides and roof a multitude of loops with its 

 hair-like threads. Along these the drop sometimes 

 runs, a drop running continuously along one end 

 forms a hook, when a drop runs along each end it forms 

 in course of time a loop, and such is the mystery. In 

 the outer part of the cave I saw some curious encrust- 

 ations. A miniature moss bends out to the light, and 

 the rock side to which it is attached is a roughed plane 

 of mosses in stone, all turning to the light. The dead 

 remained fixed in the attitude of the living.' 



' Wednesday evening. 



' I have been across the ferry in the little boat I had 

 yesterday, and after spending several hours in hammer- 

 ing among the strata of that fine section of Old Red 



