590 Manufacture of Glass. 



3d. The rims round the mouths of the bottles have not been neat- 

 ly fixed on, nor the mouths well rounded. 



4th. The bottles are much thicker on one side than the other, 

 especially near their bottoms. 



5. With regard to these imperfections, (bearing in mind that this 

 is the first attempt I have made to produce an article superior to 

 common " kanch," of which all the country glass is made,) the first 

 is the principal one, and it arises chiefly from the small scale on 

 which the experiment was made, as the pots did not contain twenty 

 pounds of glass each, and the heat was only kept up for ten hours ; 

 but in English glass houses,t he pots hold from one to two thousand 

 pounds each, and the heat is kept up from forty-eight to sixty hours ; 

 so that on a larger scale, and by a longer continued heat, this fault 

 would vanish. 



6. The remaining three imperfections are entirely mechanical, and 

 with able workmen, would cease to exist. It appears that in England, 

 (vide Gray's Operative Chemist, page 557,) six persons are employed 

 in the blowing of a single glass quart bottle, whereas I could only 

 procure one glass blower in the whole of the city of Furruckabad, and 

 this man had never been in the habit of operating upon any thing 

 better than common country " kanch," which is very fusible, and so 

 overdosed with alkali, as to be soluble in water. 



7. I must observe, that the glass blowers of this country are able 

 to work up English flint glass, the melting point of which is much 

 lower than green bottle glass, and that various articles of flint glass 

 are made at Delhi and Lucknow from broken English white glass, 

 which they purchase for five or six Rupees a maund ; but to melt 

 green bottle glass is entirely beyond their power, as they possess no 

 furnaces or pots capable of bearing the requisite heat. Flint glass 

 melts, as stated by Nicholson, (article Glass,) at the temperature of ten 

 degrees wedgewood ; blown glass at thirty; and bottle glass at forty- 

 seven. Now although the degrees of heat here stated may not be 

 perfectly correct, still they may be supposed to be relatively so, 

 which will easily account for the native glass blowers failing in all 

 their attempts to melt bottle glass. It is also I believe impossible 

 for them to melt crown, i. e. window glass, (although they can bend 

 it,) the melting point of which is so much below that of bottle glass. 



