Chapter XIV: Appendix: 3

OBSERVATIONS OF THE MEAN MAGNETIC INCLINATION, MADE ON SHORE IN THE VOYAGE OF H.M.S. RATTLESNAKE, BY LIEUTENANT J. DAYMAN, R.N.

INSTRUMENTS EMPLOYED: ROBINSON'S 6-INCH INCLINOMETER; FOX'S DIPPING APPARATUS.

The following tables contain the absolute determinations of the magnetic inclination and declination made in the Voyage of H.M.S. Rattlesnake on shore. A very large series made almost daily at sea with Fox's instrument and the Azimuth Compass require several corrections before they are fit for publication.

In degrees, minutes and seconds.

...

MADEIRA.

In Mr. Veitch's verandah, Funchal, by Robinson's Needle, A: 59 41 7 N. In Mr. Veitch's verandah, Funchal, by Fox's Needle, A: 60 40 2 N. On the summit of the Pico dos Bodes, by Fox's Needle, A: 64 10 5 N. Ther. 64. on the summit of the Pico dos Bodes, angle of deflection, 2 grains by Fox's Needle, A: 33 13 6. Ther. 59. Funchal angle of deflection, 2 grains by Fox's Needle, A: 38 8 8.

RAT ISLAND, RIO DE JANEIRO.

By Robinson's Needle, A1: 12 15 1 S. By Robinson's Needle, A2: 12 19 1 S. Mean: 12 17 1 S.

SIMON'S BAY, CAPE OF GOOD HOPE.

In the dockyard near the Observation spot of Erebus and Terror, by Fox's Needle A, with index error applied : 53 40 0 S.

TONNELIER'S ISLAND, PORT LOUIS, MAURITIUS.

By Robinson's Needle, A1: 53 48 9 S. By Robinson's Needle, A2: 53 48 8 S. Mean: 53 48 8 S.

HOBART, VAN DIEMEN'S LAND.

At the Magnetic Observatory, Ross bank, by Robinson's Needle, A1: 70 36 0 S. At the Magnetic Observatory, Ross bank, by Robinson's Needle, A2: 70 41 5 S. Mean: 70 38 7 S.

PORT JACKSON.

On Garden Island, by Robinson's Needle, A1: 62 45 3 S. On Garden Island, by Robinson's Needle, A2: 62 47 7 S. Mean: 62 46 5 S.

PORT CURTIS, NORTH-EAST COAST OF AUSTRALIA.

On Facing Island, by Robinson's Needle, A1: 51 28 9 S. On Facing Island, by Robinson's Needle, A2: 51 30 9 S. Mean: 51 29 9 S.

NUMBER 1 PERCY ISLAND.

In a sandy Bay, on North side of Island, by Robinson's Needle, A1: 49 3 5 S. In a sandy Bay, on North side of Island, by Robinson's Needle, A2: 49 0 2 S. Mean: 49 1 8 S.

KEPPEL ISLAND.

In a small Bay, on North side, by Robinson's Needle, A1: 50 46 6 S. In a small Bay, on North side, by Robinson's Needle, A1: 50 49 6 S. Mean: 50 48 0 S.

MORETON BAY.

Near the North-west end of Moreton Island, by Robinson's Needle, A1: 55 20 1 S. Near the North-west end of Moreton Island, by Robinson's Needle, A2: 55 13 5 S. Mean: 55 16 8 S.

PORT PHILLIP.

Near Captain Bunbury's House, Williamstown, by Robinson's Needle, A1: 67 12 7 S. Near Captain Bunbury's House, Williamstown, by Robinson's Needle, A2: 67 16 7 S. Mean: 67 14 7 S.

PORT DALRYMPLE.

In Lagoon Bay, by Robinson's Needle, A1: 69 29 0 S. In Lagoon Bay, by Robinson's Needle, A2: 69 19 5 S. Mean: 69 24 2 S.

SWAN ISLAND, BANKS STRAIT.

Near the Lighthouse, by Fox's Needle B, with index error applied: 68 56 1 S.

PORT JACKSON.

On Garden Island, by Robinson's Needle, A1: 62 48 9 S. On Garden Island, by Robinson's Needle, A2: 62 39 1 S. April 1848 Mean: 62 44 0 S.

ROCKINGHAM BAY, NORTH-EAST COAST OF AUSTRALIA.

On Mound Islet, by Robinson's Needle, A1: 44 15 5 S. On Mound Islet, by Robinson's Needle, A2: 44 10 6 S. Mean: 44 13 0 S.

NUMBER 2 BARNARD ISLAND.

On the West Point of the Island, with Fox's Needle C, with index error applied: 44 8 8 S.

LOW ISLES, TRINITY BAY.

On the North Point of North Low Islet, with Fox's Needle C, with index error applied: 42 22 4 S.

LIZARD ISLAND.

On the West side of the Island, by Robinson's Needle, A1: 39 32 9 S. On the West side of the Island, by Robinson's Needle, A2: 39 31 8 S. Mean: 39 32 3 S.

NUMBER 5, CLAREMONT ISLE.

On the North side of the Island, by Robinson's Needle, A1: 38 11 9 S.

CAPE YORK.

In Evans Bay, by Robinson's Needle, A1: 33 10 2 S. In Evans Bay, with Fox's Needle C, with index error applied: 33 8 4 S. Mean: 33 9 3 S.

PORT ESSINGTON.

In Proa Bay, 1 mile west of Settlement, with Fox's Needle C, with index error applied: 35 14 6 S. On board the ship, at anchor at Port Essington, same needle corrected for local attraction and index error: 33 48 0 S.

Note: The observations on board the ship at this station are the nearest to the truth, there being much ironstone strewed over the country about the observation spot onshore.

PORT JACKSON.

Garden Island, by Robinson's Needle, A1, March 1849: 62 44 2 S.

MORETON BAY.

On the North-west side of Moreton Island, by Robinson's Needle, A1: 55 21 3 S.

CORAL HAVEN, LOUISIADE ARCHIPELAGO.

On a patch of Coral near Pig Island, by Robinson's Needle, A1: 32 35 2 S. On a patch of Coral near Pig Island, by Fox's Needle, with index error applied: 32 33 0 S. Mean: 32 34 1 S.

DUCHATEAU ISLANDS, LOUISIADE ARCHIPELAGO. On the Middle Island, by Robinson's Needle, A1: 32 48 6 S. On the Middle Island, by Fox's Needle B, with index error applied: 32 56 4 S. Mean: 32 52 5 S.

CAPE YORK.

In Evans Bay, by Robinson's Needle, A1: 33 22 4 S.

BRAMBLE CAY, SOUTH COAST OF NEW GUINEA.

By Fox's Needle B, with index error applied: 31 49 2 S.

GARDEN ISLAND, PORT JACKSON.

By Fox's Needle A, corrected for index error etc.: 62 44 9 S. By Fox's Needle B, corrected for index error etc.: 62 44 9 S. By Fox's Needle C, corrected for index error etc.: 62 44 9 S.

BAY OF ISLANDS, NEW ZEALAND.

Near Kororareka Bay, by Fox's Needle A, corrected for index error: 59 37 6 S. Near Kororareka Bay, by Fox's Needle B, corrected for index error: 59 44 2 S. Near Kororareka Bay, by Fox's Needle C, corrected for index error: 59 28 1 S. Mean: 59 36 6 S.

EAST FALKLAND ISLAND.

Near the Chaplain's House at Stanley, by Fox's Needle A, corrected for index error: 52 19 6 S. Near the Chaplain's House at Stanley, by Fox's Needle B, corrected for index error: 51 43 3 S. Near the Chaplain's House at Stanley, by Fox's Needle C, corrected for index error: 50 58 8 S. Mean: 51 40 6 S.

Zh Observation spot of the Erebus and Terror near the old settlement, Berkeley Sound, by Fox's Needle B, corrected for index error: 51 25 6 S.

FAYAL, AZORES.

In the Consul's garden, Horta, by Fox's Needle B, corrected for index error: 66 58 4 N. In the Consul's garden, Horta, by Fox's Needle A, corrected for index error: 67 26 9 N. Mean: 67 12 6 N.

...

The following absolute determinations of the magnetic disinclination were made with a declinometer, and A.M. and P.M. azimuths of the sun:

William Town, Port Phillip: 9 10 52 E.

Lagoon Bay, Port Dalrymple, Van Diemen's Land: 10 29 16 E.

Garden Island, Port Jackson, March and April 1848: 9 6 43 E.

Mound Islet, Rockingham Bay, North-east Coast of Australia: 6 19 43 E.

Lizard Island, North-east Coast of Australia: 5 46 7 E.

Evans Bay, Cape York, North coast of Australia: 4 42 31 E.

Garden Island, Port Jackson,March and April 1849: 10 9 10 E.

Moreton Island, East coast of Australia: 9 21 14 E.

Coral Haven, Louisiade Archipelago: 7 44 17 E.

Duchateau Isles, Louisiade Archipelago: 7 44 17 E.

Bramble Cay, South-east Coast of New Guinea: 4 22 37 E.

Kororareka Bay, Bay of Islands, New Zealand: 13 27 20 E.

Stanley, East Falkland Island, July 1850: 16 54 46 E.