THE 



PHILOSOPHICAL MAGAZINE. 



I. Facts illustrative of the Shrinkage and Expansion of Cast 

 Iron, ^c. &'c. Bij David Mushet, Esq. of the Calder 

 Iron Works *. 



X HE high temperature requisite to melt cast iron has pre- 

 vented the chemical and philosophical world in general from 

 becoming acquainted with many of its habitudes and pecu- 

 liarities in the different staaes of manufacture. Those en- 

 gaged in foundries are frequentl)^ prevented, from the hurry 

 and bustle which attends manufactories, from making ob- 

 servations, and acquire no habit of detailing them. Others 

 again, from their earliest infancy, have been accustomed to 

 observe, that certr.in appearances, time out of mind to them, 

 had alwavs followed certain actions performed. They ac- 

 quire a laconic habit of reasoning ; and if asked how such 

 appearances are to be accounted for, their answer is, 

 " They must exist so and so — it is in the very nature of 

 the thing." 



Jt is difficult to conceive a more ample field for observa- 

 tion than an extensive foundry. Combination, change, 

 decomposition, combustion, and deflagration, are constantly 

 performing their respective parts, and continually presenting 

 matter under new and interesting appearances. 



Elementarv substances, subject to no real change, are 

 modified in a variety of ways by the alternation of heat and 

 cold. The laws which govern these are constantly exerted 

 to produce effects equivalent to the exciting cause; and, 

 while we often remain heedless spectators, these unerring 

 operations are productive of phaenomena which frequently 

 elude our sagacity or puzzle our judgment. 



The subject of contraction and expansion appears simple, 

 and the presence or absence of caloric alone in the body 



___^ * Com municated by the author. 



Vol. XVIIl.No. Gy. A 2 operated 



February lfa04. 



