Variable List
The variable list provides summary information on variables of the Voyages Database in the "Search the Database" section. The variables are displayed here in the form of short labels. The second column gives their equivalents in the downloadable SPSS version of the database, where variable names take the form of acronyms. These names are also used in downloads of data for listings, tables and graphics from the website.
Most variables are "data variables" - information as found in a primary source documenting a slaving voyage. Some are "imputed variables" indicated by IMP. They include information, such as Flag IMP which indicates what our researchers think is the likely nationality of the vessel when hard information on registration is missing, and Slaximp and Slamimp variables showing the likely numbers of captives on board at departure and arrival. Although not directly documented, these imputations are based on patterns observed in data variables.
| Variables | SPSS | Voyages | Estimates | Note |
|---|---|---|---|---|
| Ship, nation, owners | ||||
| Voyage identification number | voyageid | 36,002 | ||
| Voyage in 1999 CD-ROM | evgreen | 26,507 | ||
| Vessel name | shipname | 34,367 | ||
| Flag | national | 26,465 | ||
| Flag (IMP) | natinimp | 33,822 | • | Flag regrouped into seven major national carriers |
| Place constructed | placcons | 9,186 | ||
| Year constructed | yrcons | 6,264 | ||
| Place registered | placreg | 7,464 | ||
| Year registered | yrreg | 4,903 | ||
| Rig | rig | 23,583 | ||
| Tonnage | tonnage | 17,642 | ||
| Standardized tonnage IMP | tonmod | 16,602 | Converted to pre-1786 British registered tons | |
| Guns mounted | guns | 6,166 | ||
| Vessel owners | owner | 21,386 | ||
| Voyage Outcome | ||||
| Particular outcome of voyage | fate | 36,002 | ||
| Outcome of voyage for slaves | fate2 | 36,002 | Derived from particular outcome | |
| Outcome of voyage if ship captured | fate3 | 36,002 | Derived from particular outcome | |
| Outcome of voyage for owner | fate4 | 36,002 | Derived from particular outcome | |
| African resistance | resistance | 36,002 | ||
| Voyage Itinerary | ||||
| Place where voyage began IMP | ptdepimp | 31,526 | Same as data variable in most cases, but derived from port of return for certain Brazilian voyages | |
| First place of slave purchase | plac1tra | 21,754 | ||
| Second place of slave purchase | plac2tra | 2,787 | ||
| Third place of slave purchase | plac3tra | 552 | ||
| Principal place of slave purchase IMP | mjbyptimp | 34,319 | • | Place where largest number of captives embarked |
| Places of call before Atlantic crossing | npafttra | 1,680 | ||
| First place of slave landing | sla1port | 25,617 | ||
| Second place of slave landing | adpsale1 | 1,271 | ||
| Third place of slave landing | adpsale2 | 86 | ||
| Principal place of slave landing IMP | mjslptimp | 31,734 | • | Place where largest number of captives embarked |
| Place where voyage ended | portret | 10,706 | ||
| Voyage Dates | ||||
| Year arrived with slaves IMP | yearam | 36,002 | • | Standard variable for classification by year of voyage |
| Date voyage began | date_dep | 26,465 | ||
| Date trade began in Africa | date_buy | 8,830 | ||
| Date vessel departed Africa | date_leftAfr | 11,087 | ||
| Date vessel arrived with slaves | date_land1 | 24,280 | ||
| Date vessel departed for homeport | date_depam | 6,358 | ||
| Date voyage completed | date_end | 11,376 | ||
| Voyage length, homeport to slaves landing (days)* | voy1imp | 12,995 | Difference between date voyage began and date vessel arrived with slaves | |
| Middle passage (days | voy2imp | 7,094 | Difference between date vessel left Africa and date it arrived with slaves | |
| Captain and Crew | ||||
| Captain's name | captain | 31,943 | ||
| Crew at voyage outset | crew1 | 12,718 | ||
| Crew at first landing of slaves | crew3 | 2,281 | ||
| Crew deaths during voyage | crewdied | 4,450 | ||
| Slave (numbers) | ||||
| Number of slaves intended | slintend | 7,294 | ||
| at first place of purchase | ||||
| Slaves carried from first port of purchase | ncar13 | 1,899 | ||
| Slaves carried from second port of purchase | ncar15 | 1,889 | ||
| Slaves carried from third port of purchase | ncar17 | 1,871 | ||
| Total slaves embarked | tslavesd | 8,297 | • | |
| Total slaves embarked IMP | slaximp | 34,025 | • | |
| Number of slaves arriving at first place of landing | slaarriv | 18,347 | • | Estimated embarkations |
| Number of slaves disembarked at first place of landing | slas32 | 2,943 | • | |
| Number of slaves disembarked at second place of landing | slas36 | 2,446 | • | |
| Number of slaves disembarked at third place of landing | slas39 | 2,365 | • | |
| Total slaves disembarked IMP | slamimp | 33,713 | • | Estimated disembarkations |
| Slave (characteristics) | ||||
| Percentage men | menrat7 | 3,466 | ||
| Percentage women | womrat7 | 3,463 | ||
| Percentage boys | boyrat7 | 3,457 | ||
| Percentage girls | girlrat7 | 3,452 | ||
| Percentage male | malrat7 | 3,938 | ||
| Percentage children | chilrat7 | 4,181 | ||
| Sterling cash price in Jamaica | jamcaspr | 954 | ||
| Slave deaths during middle passage | vymrtimp | 6,456 | ||
| Mortality rate IMP | vymrtrat | 6,423 | • | Documented or difference between embarked and disembarked captives (data variables) |
| Source | ||||
| Source | source | 35,987 |