The Henri-Louis Duhamel du Monceau papers consist of manuscripts, correspondence, and memoranda related to naval activities such as ship design, port installation and maintenance, navigation, and the sailors themselves. Many of the letters and memoranda are neither to nor from Duhamel, but appear to have been referred or copied to him because of his position as Inspector General or because of his interests. The documents in this collection often lack a desirable identifier, such as the name of the addressee, sender, or date. However, there are a large number of expected names such as ministers, secretaries, port intendants, commanders, ship designers, officers, and administrators. In most cases, item-level descriptions have been provided so that the researcher can use the original descriptions and translations provided by earlier processors. The entire collection is in French; it is unknown who provided the English translations for the item descriptions. A copy of the original inventory of the collection can be found in the collection register. This collection has been divided into six series. All of the large drawings, sketches, plans, and engravings were removed from this collection, and added to the Peabody Essex Museum's Maritime Art and History department's collection.

Series I. Ship Design and Shipbuilding consists of six subseries containing memoranda, correspondence, and manuscripts relating to all aspects of designing and building naval vessels. Subseries A. General Ship Design and Building contains construction plans, instructions for performing different calculations and measurements, comparisons to English shipbuilding, and manuscripts. The first manuscript in the subseries, which says "Pour la Construction des Vaisseaux" on the cover, is partly in the hand of Duhamel, and is probably the first chapter of Elemens de l'Architecture Navale. The next manuscript, "Idee de la [construction]," gives the methods of construction used at the end of the seventeenth century into the beginning of the eighteenth century. According to Clément Denoy, this manuscript was written between 1715 and 1735; the material and its corresponding drawings were incorporated into Architecture Navale which was printed in 1752. The text and plates have additions and changes in the hand of Duhamel.

Subseries B. Wood for Building contains reports on different types of wood, dimensions of the pieces of wood for different locations on the vessels, and memoranda about wood from different regions. Subseries C. Rope Making and Strength contains test results about different types of ropes, memoranda on different types of rope and hemp, sales records of rope in certain areas. This subseries also contains correspondence about tests, experiments, and results on rope and rope making. Subseries D. Preservation of Wood and Rope contains correspondence and manuscripts about using tar as a preservative for rope and wood, its composition, methods for applying, and effectiveness. There are also documents discussing tests and comparisons of different types of preservatives.

Subseries E. Pumps contains comparisons of different types of pumps that were in use, descriptions of new pumps, and correspondence about types of pumps. In box 6, folder 11, one of the manuscripts is an explanation of a diagram of a specific pump. The diagram has been removed from this collection, and is in the Maritime Art and History department's collection, item numbers M10433 and M10435.

Subseries F. Miscellaneous Ship Equipment contains correspondence, memoranda, and drawings about other parts and materials of ships, such as dividers, nails, and capstans.

Series II. Cartridge Paper contains memoranda and correspondence about cartridge paper for the use in cannons. The majority of the documents are about a manufacturer named Mr. de la Roche; however, there is some correspondence about other manufacturers.

Series III. Ports and Port Installations contains memoranda and correspondence about enlarging and improving ports, and memoranda on the need for improvements, particularly at the Port de Bouc. This series also contains reports and memoranda about dry docks, including comparisons to some outside of France.

Series IV. Miscellaneous Correspondence contains correspondence not related topics in the other series in this collection. Many of the letters are neither to nor from Duhamel, but appear to have been referred or copied to him because of his position as Inspector General or because of his interests.

Series V. Navigation contains reports, descriptions, and recommendations about new instruments. There are also essays, treaties, and notes on instruments for navigation. Series VI. Ship Personnel, Operations, and Health contains reports and memoranda on a number of topics such as: removing bad air from the ship, shortage of surgeons, laundry, food and liquid provisions and the preservation of such, Russia's method of salting and how they cured scurvy, and keeping water fresh on long voyages. Also included in this series are the names of personnel, memoranda about the need to educated superintendents, what the duties of the Secretary of War and Marine should be, and criticism and remarks about the Department of War's maritime fortifications.