Maggs Bros.

A fascinating letter, sounding the alarm of incoming plague from Algiers and outlining the initial public health measures taken to stop the spread. It lays the blame on Algerian corsairs, who are said to have infected foreign ships, the crews of which have then passed the disease on in various ports and their home countries.

The letter thus orders the Governor of the Tower of Saint Vincent to stop any vessel (Portuguese or foreign) approaching Lisbon harbour, and hold it at sea until clearance is granted by the Department of Health. It states that all small boats are to be checked, even fishing smacks going out just beyond the bar. In that way, fishing and other local maritime activity were allowed to continue, with the necessary precautions taken on their return each evening.

Manuscript material on efforts to control the plague in eighteenth-century Europe is fairly common, as the threat was so consistent and widespread. Examples linking it to piracy or privateering, however, are decidedly uncommon. This example is especially scarce, as (anecdotal) evidence of corsairs spreading disease from North Africa to the Iberian Peninsula.