Ireland
Centenary of announcement of the discovery of Quaternions by Sir William Rowan Hamilton.
| Country: | Ireland |
| Type: | Postage stamps |
| Series: | William Rowan Hamilton |
| Nominal: | ½ p |
| Year: | 1943 |
| Size: | 20 x 24 mm |
| Perforation: | comb 15 x 14 |
| Mintage: | 28,079,520 |
William Rowan Hamilton
 William Rowan Hamilton |  William Rowan Hamilton 0.12$ |