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Frequently Asked Questions

Some Extra Explanations

Here you can find answers to questions which are not (easily) found on the blog itself often asked.

The Blog Itself


Crew on Board

Money, Accounts and Weights


Enslaved Persons on Board

The Blog Itself

Why was the text not translated to 18th century English?

Any translation of a text is impossible without a certain amount of interpretation. We chose to keep this at a minimum by translating the main gists of the texts to simple, modern English. Although this too incorporates some interpretation, the historical research needed to translate to 18th century English would require even more interpretation.

Where can I find the number of enslaved persons bought so far?

If you go back to the main page with the map and route, you will find a timeline at the bottom. Below the timeline there are seven columns containing basic information of the voyage to the current point, such as the weather, wind direction and strength, distance traveled so far, and also the number of enslaved persons bought up to this point.

Do the days of the week in the past coincide with those in the logbook?

No, these do not coincide. The 12th of January for example, was a Tuesday in 1762 and a Sunday in 2014.

Are there blueprints of the ship?

Unfortunately we do not possesses the original blueprints anymore.  However, we were able to build a virtual reconstruction of the ship using information from the other documents and from other contemporary sources. See ‘The Ship the Unity’.

Where can I find a glossary of terms?
We are in the process of putting together a glossary of terms. For now, the following options can be used:

  • Tooltips – Unknown or very specific terms are explained on the blogpost itself.  They are highlighted pink, and moving your cursor across the word will give the definition and/or explanation.
  • Menu – The Menu contains a wealth of information on a variety of topics and aspects of the voyage.  It explains many of the words which crop up in the logbook and other archival documents.  You can use the keyword search to search for specific words.
  • Online dictionary – The Oxford English Dictionary.
  • Ask us! You can leave a comment or questions at each day’s blogpost, which will be answered by our staff.


Why does the position of the ship given in the logbook differ from the one given on the timebar on the main page?

This is because the coordinates of the logbook differ from current-day coordinates in two respects: they used a different prime meridian and they did not use negative numbers.  The Greenwich prime meridian did not enter use until the 19th century –the logbook uses a prime meridian at  16°40’, on current-day Tenerife (Canary Islands).  The logbook coordinates have been adapted to this.  The logbook also uses a scale of 360 for longitude degrees, instead of 180 Eastern and 180 Western longitude. These too have been corrected.

What is the relationship between the current coordinates and those from the logbook?

See question above.

Why does the position of the ship in the logbook differ from its position on the map?

Naturally, the First Mate did not have modern navigational resources. He was therefore unable to calculate his position exactly – he could only provide an estimate. In addition to this, the old map (dating from the late 17th century) is far from an exact reproduction – as with ship navigation, old map makers could only estimate the geographical locations.  Finally, the Greenwich prime meridian did not enter use until the 19th century –the logbook uses a prime meridian at  16°40’, on current-day Tenerife (Canary Islands).  The logbook coordinates have been adapted to this.
It was impossible for us to check the extent to which the old map deviates from The Unity’s voyage. The circles on the map therefore indicate an approximation of the ship’s location, although this differs only a few minutes from the First Mate’s account. Taking into account the 18th century navigational methods and using other sources, we arrived at the position on the timeline. This therefore remains an approximation of the position. See also ‘Voyage on the Map.

Which 0-meridian is used to calculate the position in the logbook and on the map?

See the answer above.

What is the average distance the ship travels per day, and why does this sometimes seem so low according to the logbook?

The distance traveled by the ship differs per stage of the voyage. During the trip to Africa this was about 110 km per day, while the average during the Atlantic crossing was 125 km per day. Trade in Africa took up much more time however, and often the ship would remain in one place for days, or even weeks.  This lowers the average of the entire voyage to about 9 km per day.

Crew on Board

What happened to the wages of a crew member if he died during the voyage?

The deceased crew member’s wages were paid out to his family until the day he worked. His personal effects were auctioned off to the remaining crew members. The proceeds went to the deceased’s family, after  expenses (such as firing a shot to honour the dead) were deducted.  We already have two examples of such an auction on the site: December 24th, 1761 and January 2nd, 1762. The documents can be found under the heading ‘Context’ above the post itself.

Why is there no captain’s logbook?

Unfortunately the logbook of captain Menkenveld was either not preserved, or never written. This is also the reason we use First Mate Pruijmelaar’s logbook. We do possess the more rare Surgeon’s logbook, written by doctor Couperus. His entries, when they occur,  are published next to the First Mate’s entries.

Did the crew go ashore?

Certainly the crew would have been able to go ashore in the ports entered by The Unity, especially those in Europe and West-India. It would have been more difficult to do so in West-Africa, since the ship mostly traded via canoes, eliminating the need to physically go ashore.  The boat was also used for trade, in which case it was manned by either the captain or one of the mates, with some extra crew members.  In one case the carpenters had to row the boat to Elmina for repairs.

Was there any kind of entertainment on board in the shape of music, singing or games?

According to the inventory there were two drums on board The Unity. One or more of the crew members would have fulfilled the function of drummer: the drummer signaled the changing of the watches, and when the boat or rowboat left the ship, arrived ashore or arrived from other ships. We know from some other ships that they had trumpeters.  Games were also played on board, often mime games or theater games. Card and board games were also played (though cards were often forbidden on Sundays), while gambling (dice or cards) was always forbidden.

How, if at all, was the Christian faith acknowledged on board?

This differed. Sundays were not exempt from trade (see for example January 10th, 1762). We do know that the captain had received instructions concerning public prayer. The prayer was to be held each morning and evening: at six p.m. in the evening and probably also at 6 a.m. in the morning. Everyone had to be present for this; whoever was not, or whoever misbehaved, was fined 6 shillings, earmarked for the ‘seafaring poor’.

The First Mate does not have anything to say about any other Christian services, such as doing some extra for Chrismas. This doesn’t necessarily mean that there was no recognition of the Christian feast whatsoever, since Christmas has been celebrated by the church since the beginning of the 18th century; New Year’s had already been celebrated on January 1st since 1583.

Why were decks sprayed with lime juice?

This was mostly a hygienic measure, probably to combat the smell. Once the day the enslaved persons had their meals above decks, at which point the decks where they were held were scrubbed and cleaned completely, often with lime juice.

Why were there declarations of the ship’s council?

Loss to and damage of trading goods or the ship itself had to be accounted for to the board in Middelburg. These declarations, written and signed by members of the council and eyewitnesses, could be used by the captain (or any other crew member) to prove that such a loss was not his fault – and therefore not his to compensate.

Money, Accounts and Weights

How does the money system work?

In the 17th and 19th centuries Dutch traders used guilders or Flemish pounds in their accounts:

  • 1 guilder = 20 shillings
  • 1 shilling = 16 pennies
  • 1 Flemish pound = 20 shillings
  • 1 shilling = 12 pennies
  • 1 Flemish pound is 6 guilders

For more information on the calculations themselves, see Trade Book

Why do some of the sums in the accounts not seem to add up?

This is because a different coinage system was used at the time. See Trade Book for further details.

Why did they sometimes use fractions in their calculations?

For some of the goods (eg. copper goods) they calculated in sum per pound (a unit known as ‘libra’, shortened to lb.). Because they used such a small-scaled unit, some of the sums ended up with a fraction per unit, resulting in fractions. The confusing usually stems from misreading the colon for a comma.

Why is the value of traded goods indicated with money?  Did they use money along the coasts of Liberia, Ivory Coast and Ghana?

All the goods taken by The Unity for trade were converted to their money value. That way the captain could give a good account to the board in Middelburg. The goods traded for enslaved persons were also converted into money, and noted down at the end of the bill. This therefore does not mean that money was actually used along the West African coast, but merely that the goods had been standardized by the captain for easy reference and calculations.

Who was held accountable to the board in Middelburg for the loss of enslaved persons?

Unfortunately we’re not sure. The captain held the final responsibility for the voyage, and was held accountable for it in Middelburg. In those cases where the captain was not guilty of loss or damages of goods, eyewitness accounts were written down and signed by members of the ship’s council as evidence. However, none of these declarations concerned the enslaved persons, leaving us in the dark in this particular issue.

From February 10th (at Grand-Lahou, Ivory Coast) onwards they suddenly start noting down the weights of the goods. Why?

At this particular stretch of coast, the inhabitants only traded in gold. The value of all the goods therefore had to be converted to their value in gold – which was only possible by weighing them.


The rate at which the ship travels down the coast to purchase enslaved persons seems very slow and unorganized. Why?

The Unity had two different trading strategies for purchasing enslaved persons: for the main part of the voyage the captain would buy a small number of enslaved persons from small villages and towns along the coast wherever he could. Though unorganized, it was the only way buy human beings in these parts of the coast. These enslaved persons were often cheaper, but traveling was very slow and much less efficient. The second alternative was for the ship to remain for longer periods of time at the large trading forts along the route, such as Settra Kru (Liberia), Grand Lahou (Ivory Coast) and Elmina (Ghana). These forts traded in enslaved persons themselves, which meant that slaving captains could buy larger groups of human beings at the once. Naturally this was much more efficient – and just as naturally, more expensive.

Why does it sometimes seem as though the ship never moves on the map?

This means that the ship would remain at one location for a longer period of time, in order to purchase large groups of enslaved persons. See the answer above for more details.

Why do the number of purchased human beings in the logbook not accord with the number in the trade book from January 23, 1762 onwards?

This is because the trade book was put together in hindsight, while the logbook was kept each day. This also shows from data errors which can be found in the trade book: in the course of the voyage  the data from logbook often differs from that of the trade book.  At the very end of the voyage the enslaved person and money count of both do coincide.

Did all of the purchased trading goods need to be sold?

Of course this was the intention, but it did not always work out this way. At the bottom of the page Ivory Coast and Gold Coast is an example of unsold goods and goods which were purchased for too high a price in the Netherlands. The latter had also proven problematic at the Windward Coast. Some of the goods were also used to trade for food and water for the enslaved persons and crew.

What did the ballast consist of, and why was it necessary?

Ballast on a ship provides the ship with more draft, making it more stable. The Unity’s ballast consisted of, among other things, crude iron and water barrels. It might seem as though 300 enslaved persons and a crew of 30 would provide enough weight for ballast, but both were located too high up on the ship. Ballast was usually kept at the lowest deck of the ship.

How were goods stored on board?

The goods were packed in numbered barrels – and great care to was taken to note down which goods where stored where. The barrels were put in the hold, in the order of expected trade (some goods were meant for specific regions in West-Africa). See also ‘Cargo’.

How many goods could The Unity store on board?

See Cargo and Equipage Ship for a list of the all goods which were taken with The Unity.

What is the value in goods of an enslaved person purchased in West-Africa?

See the page Results for data and information concerning het purchase of enslaved persons in West-Africa. Specific information per person can be found in the ‘Memorial’ trade book, which can be viewed online in the archives inventory, under inventory number 384.

Enslaved persons on Board

Where was the line between girl and women, boy and man and child and small child?

Boys and girls were considered adults (in terms of price) roundabout their 17th year. Children below the age of 13 were allowed to stay with their mother, while children older were separated according to gender with the adults.

Were babies (0-1 year) purchased?

Yes. Sometimes mothers with very small children were bought, and there are at least three instances of a woman giving birth on board the ship (see Feb. 23, 1762; June 22, 1762 and Aug. 18, 1762).

Did they take the composition of the enslaved persons into account (ie, equal numbers of men, women and children?)

The captain did pay careful attention to this. Men and boys were usually more expensive than women and girls.

Who represented the enslaved persons on board the ship?

In the archive material of The Unity there is no reference to a specific ‘representative’. We do know that with other triangular voyages there was sometimes an African on board who traveled voluntarily as ‘bomba’ to facilitate communication between the enslaved persons and crew members. For this he received a sailor’s wages.

How were enslaved persons treated on board? Do we know whether they were abused?

The treatment of the prisoners could differ per voyage and captain. However, the board’s instructions to the captain contained on clear-worded paragraph on the treatment of enslaved persons on board:

“We order you emphatically to not allow any abuse of the slaves, either by het officers or the sailors. Should this happen, you will make note of this. The offender will be punished by the ship’s council, possibly with confiscation of wages.”

See also Menkenveld’s previous voyage to Suriname.

Was there ever a mutiny among the prisoners? How did the crew prevent this from happening?

There was no mutiny on board The Unity during this voyage. The captains of the MCC had strict orders to treat the enslaved persons well. We do know that during The Unity’s next voyage, with Daniel Pruijmelaar as captain, there was a mutiny.

Do we know whether the enslaved persons were afraid of being eaten?

This idea does appear in the literature, but no instances of it have been found yet in our archive documents.

How could enslaved persons jump overboard if they were chained below deck?

The enslaved persons were not kept in below deck all the time. They were allowed to sit outside on deck each day – often quite long in Africa. In the case of the sharks for example, the enslaved persons could simply sit on the ship board, and could even trade with Africans. For more information on the housing of the enslaved persons and further division of the ship, see Enslaved persons on Board.

Why do the logbooks of the First Mate and Surgeon not always coincide in their report of enslaved persons’ deaths?

In most cases the logbook of the First Mate is more accurate in most cases because it was written down per day. The Surgeon put his logbook together on the basis of notes written during the trip. In the case of April 22, 1762 for example, the Surgeon will for example have known that three enslaved persons died shortly after each other, and he noted them down on April 22, instead of two on the 22nd and one and 23rd, as the First Mate did.