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XXVIT. On the Freezing of Water in leaden Pipes, indi~ 

 eating Means for its Prevention; with some Thoughts 

 relative to the increased Temperature of the Earth at 

 small Depths, By G. J. Wright, Esq* 



X he perplexity arising from the defect of an usual source 

 of water for domestic use in the winter season, is a casualty 

 which most individuals have at one time or other experi- 

 enced, probably not less to their cost than their inconve- 

 nience. Such is the consequence inevitably ensuing from 

 the stagnation of water in leaden tubes in frosty weather, 

 particularly in exposed situations ; the tubes being not un- 

 frequently burst by that expansion during the congelation, 

 of the included water, to which if any opposition is made, 

 the hardest metals and most solid bodies give way. 



To endeavour to obviate the same by the naturally sug- 

 gested mode of surrounding the pipe with the most perfect 

 non-conductors of heat, is a method only partially applica- 

 ble, and eligible no further than the course of the pipe 

 under ground ; because the impossibility of ascertaining, in 

 a long course of covered pipe, the exact portion of the tube 

 where any rupture may have taken place, would occasion 

 the necessity of laying open the non-conducting coat for a 

 considerable length to arrive at the injured part. Neither 

 can we expect by any combination of metals to form a con- 

 duit capable of resisting the effects of external cold, they 

 being all of them good conductors of heat. On the other 

 hand, if we have recourse to compositions of an earthy na- 

 ture, as porcelain, baked clay, &c, we labour under in- 

 conveniences from the inflexibility of such tubes ; their lia- 

 bility to crack in sudden transitions from heat to cold; 

 their incapability of yielding to internal distension ; and 

 especially the thickness such tubes would require to be, in 

 order effectually to prevent the transmission of the tempe- 

 rature of the contained water to the surrounding air. 



Leaden tubes have always gained the preference as con- 

 duits for conveying water in small quantity for domestic 

 and other uses ; for, although they are liable to the casualty 

 of* bursting during frost, their valuable properties of flexi- 

 bility, ductility, and unalterableness by pure water, render 

 them well adapted for the purpose. 



Leaden pipes are usually of a certain thickness, about an 

 eighth of an inch: it is this thickness, and the ductility of 



* Communicated by the Author. 



the 



