A I M E N U I X .
, „t the circumference of a circle, and therefore haU
C F E is an angle at D E F or forty-five degrees.
C D E , atthecentre; andequaUODEF y^ ^ ^ ^ ^^^ ^
An object at H bemg here suppose to
appear in contact wxth an .t r o u g h the glass F.
be the horizon of the sea. But, ^^ really
and bringing an ol^ect — ^ ^ ^ ^ ^ ^^^ ^^ ^
forty-five degrees above . t , i „ t o contact ^ t h
and by looking ^^ ^ ^ ^ ,Ldred Ind thirty-five degrees
K, or the horaon, which >s ^ e ^ y
from i t , the index of the quadrant ^ " ^ y to go farther m
l i e principle being thus shovra, :t rs L ^ to a quint
h i s p l a L . , either in e . pWn g h o . . ^ ^ ^ ^ ^ ^ ^
tantor sextant. «if ^ has lately made with
of t a k i n g advantage of it, ui the sextant
power to measure 160^ . ^j^ent of the additional glass. 1
In adjustmg or venfymg the j g^ed stars more
found that by measuring ^ ^^
than forty degrees ^^ ^ ^ ^ ^ ^ ^as practicable to aacer- r sr»" Lix-sr- ..L. .—
use of this auxihary. „„raUel to the plane of the
graduation.
No. 45.
O N CLOUDS.
and of all sizes : sometunes it is smau. ^. d e f i n e d ; someor
dirty water ^
^oes notfailfrom it. Its exact