“Fire Ships and fire Rafts, covered by the Smoke of Cannon”?

After evacuating Boston on 17 Mar 1776, the British military was gone—and yet not gone.

The troops, their families, their support staff, royal appointees, and more than a thousand Loyalists had embarked on more than a hundred ships, but those ships were bobbing in the outer harbor.

People worried that the army or navy would attack Boston or other coastal towns, either for supplies or for revenge. The Continental forces had a few armed schooners, good for capturing isolated merchant ships but not up to taking on a royal frigate, much less a fleet.

On 21 March, Josiah Quincy wrote to Gen. George Washington about what he could see from Braintree:

Since the Ships and Troops fell down below, we have been apprehensive of an Attack from their Boats, in Pursuit of live Stock; but, yesterday in the Afternoon, we were happyly relieved, by the Appearance of a number of Whaleboats, streching across our Bay, under the Command (as I have since heard) of the brave Lieut. Colo. [Benjamin] Tupper, who in the forenoon had been cannonading the Ships, with one or more field Pieces from the east Head of Thompson’s Island; and, I suppose, last Night cannonaded them again from the same Place, or from Spectacle Island.

This judicious Manœuvre had its genuine Effect; for, this Morning, the Admiral [Molyneux Shuldam], and all the rest of the Ships, except one of the Line came to sail, and fell down to Nantasket Road; where a countless Number is now collected:

In Revenge for their burning the Castle last Night; were we provided with a sufficient Number of fire Ships and fire Rafts, covered by the Smoke of Cannon from a few Row Gallies; this Night, might exhibit, the most glorious Conflagration, that was ever seen upon the watery Element, and the probable Consequences of it, a Period to the present War, otherwise, Humanity revolts at the Destruction of so great Number, even of our Enemies.

A fireship, as Samuel Johnson defined it, was “A ship filled with combustible matter to fire the vessels of the enemy.” Sometimes they carried not just combistibles but explosives. The tactic was to send such a ship toward a group of enemy vessels, set it afire, and get off safely while it continued on. A flaming fireship was probably the most fearsome single weapon of eighteenth-century warfare. Even if it didn’t damage enemy ships, they had to scramble to stay out of its way, and captains might decide to move on.

It seems significant that the Americans at this time wrote mostly about “fire Rafts.” That seems like a cheaper form of fire ship, not able to carry as much or be steered as easily, dependent on prevailing currents.

Quincy was a senior member of the Massachusetts Council and energetic supporter of the war. Gen. Washington wrote back to him on 24 March, 250 years ago today: 

The continuance of the Fleet in Nantasket Road affords matter for Speculation—it surpasses my comprehension—and awakens all my Suspicions—I have taken every step in my power to guard against Surprizes, but the temper of your People, seems to me to be, to apprehend no danger till it stares them in the Face—

I do not think there is cause to apprehend such Marauding parties as you dread—if any stroke is aimd, it will be a capitol one, for which reason I wish to be much upon my guard; & therefore have appointed Guard Boats, lookouts, &ca—there is one evil I dread, & that is their Spies, I could wish therefore that the most attentive watch was kept to prevent any Intercourse between the Ships & Main

He urged Quincy to set up a shore guard watching for such infiltrators, promising to pay those men’s wages.

Washington sent that reply through Gen. Artemas Ward and added this order for his second-in-command:

As these favourable Winds do not waft the fleet from Nantasket, my Suspicion’s are more and more roused. I wish therefore the Fire Rafts talkd of by Colo. Tupper, could be attempted in a Windy, or dark Night, I think this would discover their designs if no other good effect resulted from it.

TOMORROW: The next day’s action.