(1773), p. 190) also gives results of measurements by Gascoigne of the diameters of the moon, Jupiter, Mars and Venus with his micrometer.
When the length of the wire exceeds 400 diameters, or thereabouts, Ho may generally be considered as equivalent to H, 10.
The error thus arising may be compensated by a rotation of the object-glass about one of the diameters y= =x.
long; lower view X3 diameters.
diameters are mostly used, the 4 in.