470 PHILOSOPHICAL TRANSACTIONS. [aNNO 1709* 



the change of the different seasons, fas I see no reason but very nearly it 

 must) it would be easy to compute, that a ship which should draw two fathoms, 

 or 12 feet water, in such weather as is understood by the greatest degree of 

 heat, whould draw about half an inch less from the greater density of the fluid, 

 when reduced to the forementioned degree of cold ; and consequently would 

 sail better at that time. And since water is thus capable of dilation and con- 

 traction by heat and cold, I see no reason why the same may not be performed 

 by force, notwithstanding the many attempts to determine it have as yet been 

 fruitless. For since the constituent parts of the fluid are capable of being 

 removed to greater distances from one another by heat, and become more closely 

 united by cold; so I conclude, that there must be some body contained in it 

 of an elastic quality, which must be subject to the same laws of such a body : 

 that is, be capable of compression by force, as well as to become more dense 

 by cold. 



•Some Experiments on the Weight of Common fVater, under different Circum- 

 stances. By Mr. Fr. Hauksbee. F. R. S. N° SIQ, p. 269. 



First, I took a glass of common water, and having nicely weighed a glass 

 bottle in it, whose bulk, was equal to the bulk of 575 grains of the fluid, I 

 then caused some of the water to be boiled over the fire ; after which, it was 

 included in vacuo, and there remained till it became of the same temperature 

 with common water. Thus I endeavoured as much as possible to extricate all 

 the air. out of the water, thinking in that state it would become more dense 

 than when I first weighed the bottle in it ; but, contrary to expectation, I 

 found that the bottle had just the same weight in it as before ; which seems to 

 confirm the impossibility to compress water by force into a less space than it 

 naturally possesses : for if, on the removal of such a quantity of air out of its 

 body, the parts do not slide any closer together, how should a weight laid upon 

 its surface, when its interstices seem to be replete with air, make any impres- 

 sion on it ? The body forced out of the water, by the foregoing means, I call 

 air, since it is subject to all the same laws with it ; but that the water, on its 

 absence, should not unite more closely than before, seems very surprising ; for 

 I cannot conceive what matter must supply the vacancies, since the particles of 

 water themselves remain at the same distances as if the air had not been 

 withdrawn, otherwise the water of necessity must become more dense. But to 

 proceed ; I caused some water to be heated about blood-warm, then weighing 

 the bottle in it, I found the bulk of water equal to the bulk of the bottle was 

 about 3 grains less than when cold; which shows that the component parts of 

 the water are easily separated by heat, and the matter lodged in its interstices 



