VOL. v.] PHILOSOPHICAL TRANSACTIONS. 541 



quick; after which, with a motion regular enough, and of middle velocity, it 

 retired back to the globe, till being come to a certain mark, it descended no 

 further, but stopped there for a while motionless. Afterwards little by little it 

 was seen to begin to rise again, but with a very slow and in appearance even 

 and regular motion; from whence, without any proportioned acceleration, it 

 suddenly and furiously started upwards ; in which time it was impossible to fol- 

 low it with our eyes, as it ran up with this impetuosity, in an instant as it were, 

 through several tens of the marked degrees. And as this violence began in a 

 moment, so in a moment it ended; for as from this very great velocity it sud- 

 denly passed to another degree of motion, which though quick enough, was 

 yet incomparably less than the preceding; and going on to rise in this degree, 

 it went to the top of the neck, and at last ran over. 



While this was going on, there were at times seen on the top of the water some 

 bubbles more or less, either aerial, or of another more subtle matter. This 

 separation was not noticed till the water had begun to take a brisk cold; as if the 

 force of such a cold had the power of straining such matter, and severing it 

 from the water, v 



Being desirous to see whether those alterations kept among themselves any 

 kind of analogy, we began to reiterate the conglaciations, and no sooner was 

 one ice destroyed, but we set it to freeze anew : And the water went to con- 

 geal again in the same order of alterations; which yet did not every time re- 

 turn to the self-same points or degrees in the neck: Which made us believe that 

 they had no constant and stable period, as reason seemed to persuade us they 

 had. Meantime, in repeating these experiments, having once unawares let the 

 water of the globe freeze near to the neck, the globe burst : Whereupon an- 

 other being taken, of a less size, in order that the cold might more speedily and 

 more easily get into all the water, and the neck of it being two braccios long, 

 that it might not run out ; it was filled with water up to the j6oth degree, and 

 then put into the ice. Here observing it as attentively as we could, we found 

 first, that all the accidents of subsiding, rising, resting, starting upwards, run- 

 ning, retarding, always followed in the same points of the neck of the globe, 

 that is, when the surface of the water stood at the same degrees; provided, that 

 in the act of setting it in the ice, care were taken to put it to the very same 

 degree where it was when put into the ice the time before, that is to say, to 

 the same temper of heat and cold : In which case the whole vessel might be 

 considered as a very nice thermometer, by reason of the great capacity of the 

 globe, and the exceeding straightness of the neck. This being provided for, 

 we began to take notice of the precise time of congelation ; which to find aright 

 after every little space of time we took up the globe out of the ice; but how 



