British Gunsights

British Gunsights evolved during the Dreadnought Era from simple quadrant sights to cam-worked species with telescopic, periscopic or open sight vanes which applied drift and ballistic corrections.

Telescopes

Telescopes were often used to provide crosshairs and a magnified view of the target.

In 1907, the following types were supplied:

Pattern Number	Manufacturer	Power	Field (degs)	Diameter (in)	Remarks
1306	Ottway	3	9.5	2
1663		3	9.5	2
1663A		3 D.N.	9.5	2	Ottway illumination
1663B		3 D.N.	9.5	2.52
1697		6	9.5	2
2110A		7-21 D.N.	4.5 - 1.5	2.52
		5-15 D.N.	6.25 - 2.33	2.52
		3 to 9 D.N.	9 - 3	2.52
2110	Ross	7 - 21	4.58 - 1.52	2.52	Ross illumination
2134		5 - 12 D.N.	5.83 - 2.92	2.52
2018	—	high	—		1.153		bore sighting
2019		low

The meaning of the "D.N." designation is unclear. "V.P." is used to mean "variable power".