Diameter of the wick-pipe within, live lines ; diameter 
of its conical border, seven and an half lines ; breadth of 
that part of its border which is raised, five lines ; breadth 
of the wick, one and an half line ; thickness after being 
prepared in melted tallow, one line ; lateral opening of 
the wick when in its place, three and an half lines. 
Dimensions of the lamp glass. Diameter below the su¬ 
perior cylindrical part, nine and an half lines ; diameter at 
the top, eleven lines ; height of the superior cylindrical 
part, five inches and three lines ; total height, six inches and 
eight lines ; interior diameter below, fourteen lines ; height 
of the inferior cylindrical part, sixteen lines. 
This lamp burning with all its brilliancy, and giving the 
light of four candles, will last for four hours and a half, 
with its complement of oil. When it diffuses no more than 
the light of two candles, it will burn for twelve hours, and 
so on in similar proportion. 
