MicroGRrapuia. 
der.. ‘This veflél being thus prepared, the way of niarking and gradus 
ating the Thermometers may be yery eafily thus performed: .... 2... 
" Fill this Cylindrical vefiel with the fame liquor wherewith: the Zhers 
wometers are fill'd, then. place both it and the Thermometer, you are to 
graduate, in water thatisready tobe frozen, and bring the furface of the 
liquor inthe Thermometer tothe firft marke or [0]; then fo: proportion 
the liquor inthe Cylindrical vetiel, that the furfaceof it may, jult be at 
the lower end of the {mall glafs-Cylinders then very gently.and gradu- 
ally warmthe water in which boththe Thermometer and this Cylindrical 
veflel ftand, and as you perceive the ting'd liquor to rife in, both ftems; 
with the point of a Diamond give feveral marks ‘on the ftem of the Thers 
mometer at thofe places, which by ¢omparing the. expanfion .in both 
Stems, are found to.correfpond to. the divifions of the cylindrical veftel; 
and having by this means marked fome few. of thefe divifionson the 
Stem, it will be very eafie by thefe to mark all the reft of the Stem, 
and accordingly to affign to every divifiona proper chara¢ter,..))) 
A Thermometer , thus marked and prepared, wil] be the fitteftInftru: 
ment to make a Standard of heatand.cold that can be imagined... For 
being fealed.up, itis not at all fubjeCt to variation, or wafting, noris it lia 
ble to be changed by-the varying preflure of the Air, which all other 
ae of Thermometers that are open tothe Air are liable to, But to proé 
-. This property of Expanfion with Heat, .and ContraGtion with Cold,: is 
not peculiar to Liquors;only, buttovallkind of:folid Bodies allo, efpecis 
ally Metals, which will more manite(Uy appear bythis Experiment, > 2 
_ Take the Barrel of a Stopeock of Brafs, and Jet the Key, which is well 
fitted to it,be riveted into it.fo that it may {lip,and be eafily turned round, 
then heat this Cock inthe fire, and ‘you will find the Key fo {wollen, that 
you will not be able toturn it round it the Barrel 5 but ifit be fuffered 
to.coolagain, asfoon.asit-is cold it will be asmovable, and as eafietobe 
turned as before. nalaas 
: ‘This Quality: is alfo vety obfervable.in Lead, Tit, Silver, Attiniony; 
Pitch,Rofn,bees-wax.Butter,and the likes\all which,if after they be ipakie 
you fuffer gently to coo} ,, you fhall find the parts of the upper, Surface 
to fubfide-and fall inwards , lofing that plumpnefs and fmoothnels it hac 
awhilftin fufion. | The liked have alfo obferved in the cooling of Glafé 
of Antimony, which does very neer approach the nature of Gla, 
o: But becaule thefe are all Examples taken. from other materials. then 
ink cedenpeaionlys ss poflibly there may be thelike property, al in 
Glafs, not that really there is 5 we Shall by three‘or four Experiments in- 
ideavour to manifelt thatalo, | 10 sibbim wrossibasD sh 3 iolust fs 
svoAnd.the Firlt isan Obfervation that is very\obvious evenin thele very 
drops;to witsthat they areal] of them terminated with an unequalor ay 
regulat'Surface . efpecially about the fmaller past of the drop,,andthe 
whole length of the fterti; as abontiDy:and fromthénce to Aj the whole 
Surfacé which: would baveibecn:vound if the. drop had coolidJeifurely, 
is, by being quenched hattily,wery.ingcgularly flarted and pitted! which 
wad iZ 
39 
