19^2 MINIMUM TEMPERATURE OF WATER. 



mixture, and gently (haken; upon which long icicles formed 

 in an inftant, projeding into the water in all diredions, irom 

 the caoutchouc to which they adhered. This experiment, I 

 have no doubt, might be made a very beautiful one by a dex- 

 terous operator, who is in the habit of exhibiting natural ap- 

 pearances to public alTemblies. 



After difcovering that water will dilate without any change 

 of temperature from warm to colder, at 32', I began to ima- 

 gine that the whole variation of expanfion under 41*', might 

 be explained on the fame principle, becaiife I believe all the 

 experiments relating to the fubjed, have been made in a cooU 

 ing medium, not warmer than melting fnow. 

 Water expands In order to try the merits of this opinion, with an inftru- 

 ky cooling be- ment larger fhan a common thermometer, I filled a four-ounce 

 ^z'degTorbe- p'^'^' ^''*^'^ water, and fixed an open tube into it, by means of 

 gins to cryftalizc a perforated cork and cement ; but this apparatus proved my 

 term.^ "^^" I'ufpicion to be falfe. For the place of the water being marked 

 on the tube when the temperature was 41^, my bulky ther- 

 mometer rofe immediately upon being plunged into water ot 

 34*^. This fad proves, that water expands by a lofs of tem- 

 perature between 41° and 32°; or elfe, that this fluid begins 

 to cryltalize at the upper term; in confequence of which the 

 lower term, or SS'^, is not, properly fpeaking, the commence- 

 ment of congelation, but the point at vthich the cryftals of 

 ^vater begin to concrete into malfesby aggregation. 

 I remain, &c. 



JOHN GOUGH. 



II. 



Account of the Art and Injlruments ufed for horiiig and blaftin^ 

 Rocks; Kith Improvements. In a Letter from G , C. 



To Mr. NICHOLSON. 



SIR, Brijiol, Jan. 21, 1S06. 



ImproTements ijY way of appendix to Mr. Clofe's remarks on the ufe of 

 tiI)Bed*'"* ""'""'^"'^ '" liemming mines in hard rocks, and his ufeful improve- 

 ment of the pricker, by making it of copper inflead of iron, 

 allyvs- mc to add two other improvements in the art of blading 



ftone, 



