604 TRANSACTIONS OF THE 



of metallic action, he makes the following quotation from another 

 writer : — 



" The first difficulty arising from this source, is the compara- 

 tively slight but constantly disorganizing force exerted ujDon 

 structures of iron or other metals, by expansion from solar heat 

 and contraction by severe cold — a difficulty great in Europe, but 

 much more formidable in tliis country, where we have such extra- 

 ordinary extremes of temperature. A distinguished scientific 

 gentleman, speaking of this subject, refers to the monument Colon 

 de la Place Vendome, erected in honor of Napoleon the 1st, and 

 covered with bronze made from captured cannon. ' In this monu- 

 ment,' he says, ' there was experienced much trouble from con- 

 traction and expansion. The bronze plates, firmly united by 

 rivets, acted as one stupendous sheet, and buckled under the sun's 

 rays in a most extraordinary manner, acting as a real great pyro- 

 meter." 



If these statements are intended to apply to cast-iron build- 

 ings — as they are doubtless meant to do — they are nothing more 

 than the reiteration of all previous writers on the subject, and 

 arise from sheer ignorance : they have been the great bugbear to 

 inventors in this department of artj for, although more or less 

 true in reference to copper, bronze, and certain other metals, they 

 are utterly unfounded when applied to cast-iron. We do not say 

 that cast-iron is without expansibility : we simply assert that the 

 temperature of our climate, throughout its utmost range, from the 

 greatest cold to the greatest heat,exerts upon it no appreciable effect. 



A complete proof of this assertion may be had, by examining 

 any of the numerous cast-iron structures, erected by Mr. Bogar- 

 dus. His factory building has now, for a number of years, been 

 exposed to every change of atmospheric temperature without, 

 and to the heat of steam boilers and the operations of a steam 

 engine and heavy machinery within — and, it should be observed, 

 his engine of twenty-five horse power is placed on the second 

 story, purposely to show the great stability of the building — and 

 yet, so perfect are all its joints, that the blade of a lancet cannot 

 be thrust into one of them; nor can there be discovered, by con- 

 tinual and close observation, where its walls adjoin the neighbor- 

 ing houses, the displacement of a single grain of dust. 



The writer of the quotation in the Americ^i Organ, continues 

 thus : 



" Although ingenious and complicated devices may have par- 

 tially overcome the effects of expansion arising from this source. 



