 | 1840 - 416 pages
...English method of manufacturing the flint plate for optical purposes is thus described : — About 71b. weight of the metal is taken in a ladle of a conical...about 14 inches by 20, and varying in thickness from |ths to ^th of an inch. This plate is afterwards annealed, and in this state goes into the hands of... | |
 | 1840 - 644 pages
...diminution of that heat is injurious to its quality. The English method of manufacturing the flint /i/i'li' for optical purposes is thus described. About 7 Ibs....of fusion, and then blown into a hollow cylinder, cnt open, and flattened into a sheet of glass of about 14 inches by 20, and varying in thickness from... | |
 | 1840 - 812 pages
...for optical purposes is thus described : — About 71b. weight of the metal is taken in a ladle o>fa conical shape from the pot at the proper point of...into a sheet of glass of about 14 inches by 20, and varyingin thickness from jthi to Jth of an inch. This plate is afterwards annealed, and in this state... | |
 | William Newton - 1841 - 468 pages
...The English method of manufacturing the flint plate for optical purposes, is thus described:—About 7 Ibs. weight of the metal is taken in a ladle of...about 14 inches by 20, and varying in thickness from fths to |th of an inch. This plate is afterwards annealed, and in this state goes into the hands of... | |
 | 1841 - 912 pages
...method of manufacturing the flint plate for optical purposes is thus described. About seven pounds weight of the metal is taken in a ladle of a conical...open, and flattened into a sheet of glass of about fourteen inches by twenty, and varying in thickness from three-eighths to one-fourth of an inch. This... | |
 | Institution of Civil Engineers (Great Britain) - 1848 - 570 pages
...heat of the blowpipe when they .are made from a metal which has been produced under all the favourable circumstances before described. It is, therefore,...about 14 inches by 20, and varying in thickness from f ths to |th of an inch. This plate is afterwards annealed, and in this state goes into the hands of... | |
 | 1841 - 466 pages
...method of manufacturing the flint plate for optical purposes is thus described. About seven pounds weight of the metal is taken in a ladle of a conical...open, and flattened into a sheet of glass of about fourteen inches by twenty, and varying in thickness from three-eighths to one-fourth of an inch. This... | |
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Jths to £th of an inch. This plate is afterwards annealed, and in this state goes into the hands of the optician, who cuts and grinds it into the requisite form. When a glass furnace is about to be put out, whole pots of metal are sometimes suffered... 