In a little brown notebook from the early 19th century on St. Martin, someone was recording the most important information they knew. The book is full of cures, remedies and other medical preparations. Most of these are notes on what was prescribed by local doctors. It is easy to understand why medical knowledge would be considered very important. For other information, the value is less obvious.
A mathematical calculation is sandwiched between treatments for ulcers and a leg sore. It is for the “dimensions of the cistern at the Estate Golden Rock.” Measurements in feet for the length, width and depth “to the vent holes” are converted to inches. These measures are converted into cubic inches to give the volume of the cistern: 967,680 cubic inches. The volume in cubic inches is then divided by 231 to give the number of gallons: 4,189.
This calculation could have been done on another piece of paper. Knowing the capacity of this particular cistern is not valuable to most people. But by recording the process of calculating the size of the Golden Rock cistern, the notebook can help anyone measure the volume of any cistern. This information could also be used to plan the size of a cistern to hold a certain amount of water.
On the other hand, this calculation doesn’t record any wisdom about how big a cistern should be. Four thousand gallons is 22 gallons a day for a six month dry spell. How many people could that support at the time?
Later in the notebook we have a page labeled “Note from Mortimer’s Commercial Dictionary.” It contains instructions for planting, raising and harvesting tobacco. The book was A New and Complete Dictionary of Trade and Commerce by Thomas Mortimer. It was written in 1766 and revised and reprinted a number of times.
Why was this particular passage copied? Did the notebook author have a chance to copy it directly from someone else’s dictionary? Was it a passage passed on from person to person? Tobacco had already been grown successfully on St. Martin for 200 years by the time this passage was written in the notebook, so why choose this information to save? Why not record information about how to grow sugar cane, the most important crop at the time?
We will probably never know why some information made it into the notebook. Perhaps some things that seem useful to record were so widely-known at the time that it didn’t seem necessary. Perhaps it was just chance that the writer had access to one bit of knowledge and not another. Do you have a theory? Share it by writing in to The Daily Herald or [email protected]