Copy letter from Edward Sabine to Major James Rennell [geographer and oceanographer, fellow of the Royal Society]
Information
Title - Copy letter from Edward Sabine to Major James Rennell [geographer and oceanographer, fellow of the Royal Society]
Record type - Archive
Original Reference - RHS/Col/2/Z1/13
Date - 11 Feb 1822
Scope & content - Written from HMS Iphigenia, off the Rio Grande [Rio Grande de Buba, Guinea-Bissau], coast of Africa
Marked 'Copy' at the top of the first page
He is sorry that he cannot write with the correct daily differences of their run by dead reckoning or by observation; he discusses the various influences of a ship's course, the weather, and differences in local attraction on the ship on its compasses and the negative effect of this on accurate navigation; the Iphigenia has experienced inconvenience from using two binnacles, as their two compasses have changing errors due to changing course and local attraction, and are used interchangeably; he suggests using only one azimuth compass would be preferable, as the error due to local attraction could be accounted for consistently, and it would be a much simpler method of navigation; on a separate sheet he has detailed general observations on the temperature and currents, which he regrets are not more conclusive; in the absence of sufficient information on the subjects chiefly occupying Davy's [Humphry Davy, chemist and inventor, president of the Royal Society] attention, he will fill his paper with an account of the new settlement in the Gambia; the site seems to have been chosen with a view to commerce and command of the river, as in terms of health and convenience it falls short; St Mary's [Banjul Island, The Gambia] is a low, sandy island, three to four miles long and one and a half miles wide, covered with mangroves, bordered by Cape St Mary's and by the entrance of the River Gambia; it is separated from the mainland by a swampy channel which overflows in the rainy season; the town of Bathurst [Banjul] is located three miles across the river from Barra [The Gambia], which would have been a better location if not for the 'indisposition and possible hostility of the natives on the Barra side'; the port is safe and convenient, and the Iphigenia experienced no difficulty in reaching the anchorage; Sir R. Mends [Robert Mends, captain of HMS Iphigenia] has recommended a house be built on Bird Island [Ile des Oiseaux, Senegal] as a landmark for ships bound in from the north; there is a shoal between the island and the Cape which is to be marked by buoys; the soundings are so regular there that they were able to navigate in a haze; the settlement has made unusually rapid progress due to its commercial convenience, with over 20 substantial stone houses built since 1817 with stores and offices attached, and 31 European residents; there is a government house, a stone barrack with defences, a hospital, a gaol, and a church is being contemplated; trade is in gold, hides and ware, and there are rarely fewer than 200 gold merchants at Bathurst trading for British commodities; the impression that Mends' visit is making on the 'native traders' is expected to prove beneficial to the settlement, and many of these traders visited the frigate, with which they were very impressed; he believes that soon the gold trade at Bathurst will exceed that of the rest of the coast; the 'impolite' wars of the French in Senegal at the start of the century stopped all British trade with the interior, but during the current period of peace the French enact little policy and so the Gambia can be expected to enjoy trade without a rival; he believes that true prosperity in the settlement will be achieved 'when the labour of the natives shall be applied to the culture of the soil' with a view to export; this should also free them from 'that detestable traffic in human kind which renders person as well as property' [slavery]; he attended a dinner hosted by the officers of the garrison on the day of his arrival, and a toast was made to the abolition of the slave trade and received with considerable enthusiasm, and he believes that soon 'the dishonour of England' will be replaced with a 'great and happy change' in Africa; the houses at Bathurst are made of stone, plastered, and whitewashed every year, with lime made from the shells of the African cockle which is found in beds on the island, giving the town a clean and neat appearance; the sand is an excessive nuisance as it is ankle deep even in the streets, and he has written to his brother [Joseph Sabine, secretary of the Horticultural Society] at the Horticultural Society to provide seeds of grasses and other plants which could bind the sand; there are three or four gardens for which he has requested tropical seeds, as their current supply is of poor quality; trees in the region provide a place for insects to breed, and the plague of mosquitoes is so intolerable that all but two Celtis trees have been cut down in Bathurst, and these spared only because they were the only two of their kind on the island and possibly the whole coast; Don believes these trees to be Celtis orientalis [Trema orientalis], a species endemic to Asia, of which the seeds could have been accidentally included in packages of goods traded from the region; he undertook his magnetic observations on the island in the shade of these trees for the whole of the second day; as the island is so valuable it is important that it is properly defended; ships pass at a distance of about two miles, which is a long distance to fire, but possible with the current set-up; a determined ship could reach the island unharmed in a fair wind despite gunfire, but if there are sufficient guns it would be an unjustifiable undertaking unless all other options had failed the assailants; a Martello tower would be very well suited to the situation; there are currently seven pieces of heavy ordnance and three mortars along the coast; if the mortars and six guns were collected in a battery at the point which projects furthest into the river, with the remaining gun mounted behind in a Martello tower, the island's defence would be ample for years to come, and he believes it may be tested by the French in the likely event of war; a well could be sunk beneath the tower to provide water; he notes that the guns are currently undermanned and observes that this would render them 'worse than useless' in an attack, and recommends sending a master gunman to train the other men on the use of ordnance so that in the event of war they will be sufficiently manned, and employing artillery soldiers instead of line soldiers as they are better trained and more disciplined; the climate would be better discussed once cultivation has taken place, and is generally unhealthy to Europeans, though he supposes it is not worse than Calcutta [Kolkata, India]; the only settlement along the coast which is healthier is Goree [Goree, Senegal], where mortality rates amongst troops did not exceed one in ten, the climate is agreeable and salubrious, and exercise can be taken at all times of the day; few settlers along the coast escape an attack of fever during the rains; the latitude of the flag staff at Bathurst by meridian altitude of the sun taken by a sextant and artificial horizon is 13°25'5''N, and its longitude by the mean of morning and afternoon altitudes and of four chronometers is 6°36'7''W; the latitude of the flag staff at Bird Island is 13°43'38''N, and its longitude is 16°43'50''W; he includes a page of data from his observations of the voyage so far including longitude, latitude, air temperature, surface moisture, wind direction and currents. Written from HMS Iphigenia, off the Rio Grande [Rio Grande de Buba, Guinea-Bissau], coast of Africa
Marked 'Copy' at the top of the first page
He is sorry that he cannot write with the correct daily differences of their run by dead reckoning or by observation; he discusses the various influences of a ship's course, the weather, and differences in local attraction on the ship on its compasses and the negative effect of this on accurate navigation; the Iphigenia has experienced inconvenience from using two binnacles, as their two compasses have changing errors due to changing course and local attraction, and are used interchangeably; he suggests using only one azimuth compass would be preferable, as the error due to local attraction could be accounted for consistently, and it would be a much simpler method of navigation; on a separate sheet he has detailed general observations on the temperature and currents, which he regrets are not more conclusive; in the absence of sufficient information on the subjects chiefly occupying Davy's [Humphry Davy, chemist and inventor, president of the Royal Society] attention, he will fill his paper with an account of the new settlement in the Gambia; the site seems to have been chosen with a view to commerce and command of the river, as in terms of health and convenience it falls short; St Mary's [Banjul Island, The Gambia] is a low, sandy island, three to four miles long and one and a half miles wide, covered with mangroves, bordered by Cape St Mary's and by the entrance of the River Gambia; it is separated from the mainland by a swampy channel which overflows in the rainy season; the town of Bathurst [Banjul] is located three miles across the river from Barra [The Gambia], which would have been a better location if not for the 'indisposition and possible hostility of the natives on the Barra side'; the port is safe and convenient, and the Iphigenia experienced no difficulty in reaching the anchorage; Sir R. Mends [Robert Mends, captain of HMS Iphigenia] has recommended a house be built on Bird Island [Ile des Oiseaux, Senegal] as a landmark for ships bound in from the north; there is a shoal between the island and the Cape which is to be marked by buoys; the soundings are so regular there that they were able to navigate in a haze; the settlement has made unusually rapid progress due to its commercial convenience, with over 20 substantial stone houses built since 1817 with stores and offices attached, and 31 European residents; there is a government house, a stone barrack with defences, a hospital, a gaol, and a church is being contemplated; trade is in gold, hides and ware, and there are rarely fewer than 200 gold merchants at Bathurst trading for British commodities; the impression that Mends' visit is making on the 'native traders' is expected to prove beneficial to the settlement, and many of these traders visited the frigate, with which they were very impressed; he believes that soon the gold trade at Bathurst will exceed that of the rest of the coast; the 'impolite' wars of the French in Senegal at the start of the century stopped all British trade with the interior, but during the current period of peace the French enact little policy and so the Gambia can be expected to enjoy trade without a rival; he believes that true prosperity in the settlement will be achieved 'when the labour of the natives shall be applied to the culture of the soil' with a view to export; this should also free them from 'that detestable traffic in human kind which renders person as well as property' [slavery]; he attended a dinner hosted by the officers of the garrison on the day of his arrival, and a toast was made to the abolition of the slave trade and received with considerable enthusiasm, and he believes that soon 'the dishonour of England' will be replaced with a 'great and happy change' in Africa; the houses at Bathurst are made of stone, plastered, and whitewashed every year, with lime made from the shells of the African cockle which is found in beds on the island, giving the town a clean and neat appearance; the sand is an excessive nuisance as it is ankle deep even in the streets, and he has written to his brother [Joseph Sabine, secretary of the Horticultural Society] at the Horticultural Society to provide seeds of grasses and other plants which could bind the sand; there are three or four gardens for which he has requested tropical seeds, as their current supply is of poor quality; trees in the region provide a place for insects to breed, and the plague of mosquitoes is so intolerable that all but two Celtis trees have been cut down in Bathurst, and these spared only because they were the only two of their kind on the island and possibly the whole coast; Don believes these trees to be Celtis orientalis [Trema orientalis], a species endemic to Asia, of which the seeds could have been accidentally included in packages of goods traded from the region; he undertook his magnetic observations on the island in the shade of these trees for the whole of the second day; as the island is so valuable it is important that it is properly defended; ships pass at a distance of about two miles, which is a long distance to fire, but possible with the current set-up; a determined ship could reach the island unharmed in a fair wind despite gunfire, but if there are sufficient guns it would be an unjustifiable undertaking unless all other options had failed the assailants; a Martello tower would be very well suited to the situation; there are currently seven pieces of heavy ordnance and three mortars along the coast; if the mortars and six guns were collected in a battery at the point which projects furthest into the river, with the remaining gun mounted behind in a Martello tower, the island's defence would be ample for years to come, and he believes it may be tested by the French in the likely event of war; a well could be sunk beneath the tower to provide water; he notes that the guns are currently undermanned and observes that this would render them 'worse than useless' in an attack, and recommends sending a master gunman to train the other men on the use of ordnance so that in the event of war they will be sufficiently manned, and employing artillery soldiers instead of line soldiers as they are better trained and more disciplined; the climate would be better discussed once cultivation has taken place, and is generally unhealthy to Europeans, though he supposes it is not worse than Calcutta [Kolkata, India]; the only settlement along the coast which is healthier is Goree [Goree, Senegal], where mortality rates amongst troops did not exceed one in ten, the climate is agreeable and salubrious, and exercise can be taken at all times of the day; few settlers along the coast escape an attack of fever during the rains; the latitude of the flag staff at Bathurst by meridian altitude of the sun taken by a sextant and artificial horizon is 13°25'5''N, and its longitude by the mean of morning and afternoon altitudes and of four chronometers is 6°36'7''W; the latitude of the flag staff at Bird Island is 13°43'38''N, and its longitude is 16°43'50''W; he includes a page of data from his observations of the voyage so far including longitude, latitude, air temperature, surface moisture, wind direction and currents
Extent - 11 page letter (3 sheets)
Repository - Royal Horticultural Society Lindley Library
Copyright - John J. Timothy Jeal
Credit Line - Courtesy John J. Timothy Jeal / RHS Lindley Collections
Usage terms - Non-commercial use with attribution permitted (CC BY-NC 4.0)