On the Compressibility of Water. - 349 
gun. This fact proves, either that the gun expands, or that 
the water enters the pores of the cast iron ; it is probable 
both these circumstances contribute to produce this effect. 
This experiment was made in America, in the year 1819, 
and before I had time to strengthen my apparatus for the 
purpose of making farther experiments, 1 was oblige 
embark for this country. On my passage, however, I had 
frequent opportunities of repeating those I had already 
made, and of making others, by a natural pressure. They . 
were as follows. The piezometer, by the assistance of fifty- 
four pounds of lead attached to it, was sunk in the ocean 
to the depth of five hundred fathoms, which is about equal 
= the pressure of one hu dred - When drawn 
Bae rc. ae aS ae ae 
pe indicating, as in the fr ts i experiment, a 
compression of one per cent. This experiment was 
times repeated, and with the same result. 
The next experiment was that of sinking a strong empty 
porter bottle to the depth of an hundred and fifty fathoms, 
having first tightly corked and sealed it, in the following 
manner. Six coverings of cotton cloth, saturated with a 
minitin, it was drawn n up. No water was found to have 
been forced into it, neither was there any visible ae at 
the mouth. 
coverings, “consisting « layers of dieik 
