TOI^. II.] PHILOSOPHICAL TRANSACTIONS. 15/ 



be carried ; which seemed to argue a motion of the under parts of the water, 

 differing from that of the upper ; a thing which is said to be at certain times of 

 the tides, both at the mouth of the Sound and of the Straits ; which deserves to 

 be further inquired into. Tiie angle made by these different motions seemed 

 to be about 40 degrees. 



5. The strength of the winds is measured by an instrument, such as is repre- 

 sented by fig. 7 ; which being exposed to the wind so as the flat side may be 

 right against it, the number of degrees on the limb A B, to which the wind 

 blows up, or raises that flat side C D, shows the force or strength of the wind, 

 in proportion to the resistance of the flat side of the instrument. 



6. The glass phial for measuring the different gravities of salt water is to be 

 made with a very narrow neck, and when it is almost full water is to be dropped 

 into it, drop by drop, till it can hold no more, drying well the phial before it be 

 weighed, having taken first the weight of the empty phial. Then by evaporating 

 gently the water till the salt be left dry on the bottom, the proportion the salt 

 of each water holds to its weight may be known. 



Mr. Boyle describes a glass tube, as is represented by fig. 8, blown at a lamp, 

 and poised in good common water, by putting quicksilver into it, till it sink so 

 low that nothing but the top appears above the water ; which done, it is to be 

 sealed up and graduated on its side into what parts you please ; which may be 

 done with a diamond. And then being put into any water to be weighed, it will 

 by its sinking more or less show the difference of the water's gravity. 



7. To fetch up water from any depth of the sea. 



Let there be made a square wooden bucket, fig. Q, whose bottoms E E are to 

 be so contrived, that as the weight A sinks the iron B, (to which the bucket C 

 is fastened by two handles D D, on the ends of which are the moveable bottoms 

 or valves EE,) and thereby draws down the bucket, the resistance of the water 

 keeps up the bucket in the position C, by which the water has a clear thorough 

 passage all the while it is descending; but as soon as the bucket is pulled up- 

 wards by the cord F, the resistance of the water to that motion beats the bucket 

 downward, and keeps it in the position G ; whereby the included water is kept 

 from going out, and the ambient water from getting in. 



By the vessel we may know the degrees of saltness of sea water, according to * 

 its nearness to the top or bottom ; or rather the nature of the sea water in 

 several depths of several climates : And whether in some places of the sea there 

 be any sweet water at the bottom ; as is affirmed in the East Indian voyages of 

 Van Linschoten, viz. that in the Persian gulph, about the isle of Baharem, sweet 

 water is fetched up from the depth of four or five fathoms. 



