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anothcr prccileiy. But vve must consider the Variation of the Weather whenwe compare the Weight of a Liquor which we Weigh in Summer time, withthe Weight of another, which we have Weighed in the Winter, for the sameLiquor being niore Rarined in the Hot time, and Condensed in the Co'd, tl.csame Volume of it will be more Wcighty in Cold Weather thanin Warm.

\A New Ejsjy H- 1 - Many Years ago I made use of a little Glast Instrument, consistingInstrument ; ot a Bubblc , and furnished with a Lang and Slender Stem to compare the Spc-by Mr. Boyle. c -ß c j^ Gravitiet of Different Liquor s by its more or less Sinkjng in Thcm : Andn! I have since employed it to dilcover the Specificis Gravitiet ot Solid, stvcral ap-

*'&• l 9i> pended , by its being more or less depressed by thetn in the stms Liqucr. For’tis clearly deducible front the Grounds of Hydrostatickj, that any Solid BodyHeavier than Water, loses in the Water as much of the Weight it had inAir, as Water of equal Bulk to the Immeried Solid wouid Weigh in the Air ;and consequcntly since Gold is by lar the mofl Ponderous of Metals, a pieccof Gold and one of Equal Weight of Copper, Brass, or any other Metal,being proposed, the Gold must be lels in bulk, than the Copper or Brass.And by this means, if both of them be Weighed in the Water, the Goldmust lose in that Liquor less of its former Weight than the Brass or Copper •because the baser Metal as well as the Gold, grows Lightcr by the weight ofa Bulk of Water equal to it; and the baser Metal being the more Volumi-naus, the correspondent Water must Weigh more than that which is corre-spondent to the Gold. Whencc I concluded, that the Floating Instrument a-bovemention’d wouid be made to sink dceper by an, Ounce, for instance ofGold, hanging at it under Water, than by an Ounce of Brass, or any otherMetal, which, by reason of its greater Bulk than Gold, losing more of itsweight by the Immersion, must needs retain less, and so have less power toDepress the Instrument ’twas fastned to. Which Conclusion will also hold(though the Disparity be not so Great and Conspicuous) in reference to otherMetals, as Lead and Tin, that differ in Specificis Gravity.

This Instrument may be of Glast, Copper , Siher, or almost any other So-lid Body, that is, or may be made, sit to Float in the Water, with a Gulny, &c.Hanging at ir, and of a Texture dose enough to keep out the Water. Itconüsts of three Parts; the Bad or Globulous pari ; the Stern or Pipe; andthat which Holds the Coin.

j .■ t The Bad or Round part BCDE (if of Metal ) consists of two thinConcave Plates, exactly Sodered together in the middle; and at the distantestparts fforn the Commissure, there ought to be lest two opposite Holet, one ineacb Plate, for the two other parts of the Instrument. This middle parr,though for Brevities sake we name it the Ball, should not be exactly Round ;but, of any Shape that Ihall be foundfit to make the Instrument keep its Erectposturc fteadily in the Water. It must contain as much Air, as may serveto keep the whole Instrument, when loadcd from Sinking beneath the top ofthe Stern.

The Stem A B, is to be Soder’d on to the Ball at the uppermost of thetwo mention’d Holet. It may be either Hollow or Solid : but it ought to be

made