1824.] Dr. Torry on Coliunbite. 359 



fusible alloy melts, must of course be considerably below that 

 at which the increased elasticity of the steam would endanger 

 the safety of the boiler. 



2. All the boilers should be proved by being submitted, by 

 means of the hydraulic press, to four or five times the working 

 pressure, for engines that work with a pressure of from two to 

 four atmospheres. Beyond that term the proof pressure should 

 as much exceed the working pressure, as the latter exceeds the 

 simple pressure of the atmosphere. 



3. Every steam-engine maker should be obliged to make 

 known his method of proving the boilers, as well as whatever 

 may guarantee the solidity and safety of his engines, especially 

 as regards the boiler and its appendages. He should also de- 

 clare this working pressure, estimated by the number of atmo- 

 spheres, or in pounds, on each square inch of surface exposed 

 to the action of the steam. 



4. For further security, the boilers of very powerful engines, 

 when near a dwelling-house, may be surrounded by a thick wall, 

 at the distance of between three and four feet from the boiler, 

 and at least as far from the party wall of the adjoining house. 



Lastly, if an exact account were taken, and published by the 

 proper authorities, of all accidents that happen to steam- 

 engines of every kind, minutely detailing both the causes and 

 effects of such accidents, with the names of the proprietors, 

 and the makers of the engines, it would mainly tend to render 

 unfrequent, though it cannot wholly obviate the evils that may 

 arise from the use of mean and high-pressure engines. 



Article IX. 



An Account of the Columbite of Haddam (Connecticut). 

 By John Torry, MD.* 



The history of columbium is recorded in almost every work 

 on chemistry and mineralogy, and is familiar to all who have 

 made those sciences their study. Though it is now twenty years 

 since Mr. Hatcuett made his interesting discovery, the only 

 North American specimen of columbite known until lately, was 

 the original one in the British Museum, and even the precise 

 locality of that is not known. It is said to have been sent many 

 years since by the late Governor Winthrop, of Connecticut, to 

 Sir Hans Sloane, their President of the Royal Society; after 

 whose death it was deposited in the Museum, where it still 

 remains. According to a notice in the eighth volume of the 

 New York Medical Repository, the locality is said to be near a 



« Annals of the Lyceum of Natural History, New York. 



