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On the Expansion of different kinds of Stone from an increase of 

 Temperature, with a Description of the Pyrometer used in 

 making the Experiments. By Alexander J. Adie, Civil 

 Engineer, 



{Read mh April 1835.) 



For a long time I was anxious to know the rate of expan- 

 sion of the common building-stone of this neighbourhood, as it 

 is not given in any of the tables of the expansions of substances, 

 because I have sometimes thought that the vertical cracks fre- 

 quently seen intersecting rubble walls might arise from the con- 

 traction caused by a diminution of temperature. During a long- 

 continued and severe frost which occurred in 1826, I thought 

 the rents in a considerable stretch of wall, which I passed at all 

 seasons, appeared more open than usual. This, however, was 

 merely conjectural, and I paid no more attention to the subject 

 until 1830, when, as I mentioned in a notice on the commencement 

 of my experiments read at the meeting of the British Association 

 in September last, an interdict of the Dean of Guild Court of 

 Edinburgh rendered the rate of expansion of stone a matter of 

 more importance than merely a curious philosophical speculation. 

 The interdict was issued against a gentleman who wished to alter 

 his property, by supporting the front on cast-iron pillars, in the 

 manner now commonly followed in this city in converting the 

 ground-floor of dwelling-houses into shops. The front of the pre- 

 mises alluded to was narrow, and of a great height; and the reasons 

 given for interdicting the operations were, that the pillars had 

 not sufficient strength to support the weight of the front, and 

 that the difference of the expansion of cast-iron and stone was so 

 great, that very prejudicial effects might arise from the use of 

 such pillars in this situation. Mr Jardine, civil engineer, was 



