204 ANNUAL OF SCIENTIFIC DISCOVERY. 



unusual violence and continuance, which affected the snows upon the 

 Sierra Nevadas. The consequence was, that the mountains poured 

 down rivers upon rivers of water, until the whole of that great basin 

 of California which the mountains bound was entirely submerged. 

 The only outlet to this water is the Golden Gate, the entrance to the 

 bay at San Francisco from the Pacific Ocean. " Take the map of 

 California," says a letter-writer, describing this flood, " and see where, 

 on the south, the mountains come to a point below Tularo Lake, and 

 then go up north to where they again join at Shasta, and then pic- 

 ture the whole of the immense tract of land they enclose under 

 water, and the Bay of San Francisco, a vast river, pouring its 

 volumes into the Pacific Ocean by the before-named Golden Gate. 

 Fancy, also, the tides of that ocean having no effect in the bay, and 

 welling up at its entrance, and you will have a feeble idea of the 

 magnitude of the volume of water that for two months ravaged 

 California. 



" It was very strange to see the sea for about ten miles around the 

 mouth of the bay. In the interior, about sixty miles from San 

 Francisco, and at the embouchure of the northern rivers, are vast 

 tracts of land covered with rushes and semi-aquatic plants, that go 

 by the name of tule lands, something like the paddy fields of India. 

 Well, as the waters rose, these immense morasses rose also, and in 

 process of time, becoming detached, floated away with the current in 

 masses of from one hundred yards to half a mile in size, and they all 

 floated out to sea, travelling, some of them, more than one hundred 

 miles before their arriving. Once arrived in their grander sphere of 

 action, it was the most extraordinary thing to see the myriads of 

 water snakes, faithful to their home, twisting and twirling in the salt 

 sea, and to see the water-fowl that screamed over their nests as 

 though warning the islands of their danger, and to see our coast 



<3 c^ C? * 



when any of the islands were thrown upon it, and the thousands and 

 thousands of snakes wriggling their way over the shrubless sands 

 that bound it for miles in search of anything to hide tfiem from the 

 wholesale slaughter that sticks and stones, and knives, and even guns, 

 made among their host. All the salt-water fish left the bay, and all 

 the oysters, like good men, died in their beds." 



THE PLASTICITY AND ODOR OF CLAY. 



In a recent paper on the above subject, read to the Geological So- 

 ciety (London), the author, Mr. C. Tomlinson, called attention to the 

 circumstance that clay is only plastic up to a certain temperature ; 

 when heated beyond that point (which the author believes from ex- 

 periments performed by him to be somewhere between six and seven 

 hundred degrees Fahrenheit), it loses its plasticity and acquires the 

 property of rigidity. Moreover, having once lost its plasticity, this 

 quality can never be restored to it by any methods yet known to 

 science. Further, this property cannot be produced artificially ; the 

 constituent elements of pure clay may be combined in the proportions 

 indicated by analysis, but the clay thus produced is not plastic. It is 

 commonly stated that it is the alumina which confers upon clay its 

 plastic property, but the author showed that pure alumina, whether 



