Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/230

204] {|align="left" style="border-collapse:collapse; text-align:right; margin-right:2em;" 212 203 194 185 176 167 158 149 140 131 80 76 72 68 64 60 56 52 48 44 122 113 104 95 86 77 68 59 50 41 40 36 32 28 24 20 16 22 8 4 32 31 30 28 26 24 23 22 20 18 0 0.44 0.88 1.77 2.66 3.55 4.— 4.44 5.33 6.22 16 14 12 10 8 6 5 4 2 0 7.11 8.— 8.88 9.77 10.66 11.55 12.— 12.44 13.33 14.22
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From this comparative view, it will appear that nine degrees of 's (between the point of natural freezing, and that of boiling heat), are equal to four of 's computation:—hence the scale of the former may be reduced to that of the latter, by multiplying the number of degrees above 32 (because 32 must be subtracted from the whole number given) by 4, and dividing the product by 9.—On the other hand, if the given degrees be multiplied by 9, and the product divided by 4, 's scale may be reduced to that of .—Upon these principles, the preceding tables are calculated, with two decimals only below the freezing point. But, if any intermediate degrees be wanted, they may be easily ascertained, by a similar arithmetical process.

It would be needless to describe the various thermometers invented during the last century; because the two instruments before mentioned have received almost universal sanction; few others being at present employed, either by artists or men of science. Hence we shall merely observe, that, at Petersburgh, contrived a new thermometer, in 1733, which is divided into 50°.—Prof. , of Lyons, proposed a scale of 100 equal parts between the freezing and boiling points: this division was adopted by Prof., in Upsala, whose improved scale, consisting of 100 exact degrees, is generally used in Sweden.

There are many other thermometers, among which, those by of Geneva; by  and, in Germany; by  in France (who, together with the three preceding, contrived the Universal Thermometer, which contains the comparative scales of 28 different instruments); by ; the ; and.

The first idea for constructing a metallic thermometer, or properly, pyrometer, was furnished by, and improved upon by , Count , and at length brought to perfection by. This ingenious manufacturer (of the finest earthen-ware from basaltic masses, or terra-cotta) has rendered an essential service to society, by his method of ascer-