List of French sail frigates  This article is a list of French naval frigates during the Age of Sail, from the middle of the 17th century (when the type emerged) until the close of the sailing era in the middle of the 19th century. The tables excludes privateer frigates (i.e. those owned by individuals or business enterprises), which were not part of the "Marine Royale", as well as frigates built for the French East India Company ("Compagnie des Indes") unless the latter were subsequently acquired by the French Navy. Note that throughout this article the term "-pounder" refers to French pre-metric units of weight - "livres" - which were almost 8% greater than UK/US units of the same name; every other maritime power likewise established its own system of weights and each country's 'pound' was different from that of every other nation. Similarly French pre-metric units of length ("pieds" and "pouces") were 6.575% longer than equivalent UK/US units of measurement ("feet" and "inches"); the pre-metric French "pied" ("foot") was equivalent to 324.8394 mm, whereas the UK/US foot equalled 304.8 mm. These differences should be taken into account in any calculations based on the units given below. Early French naval frigates, until the 1740s, comprises two distinct groups. The larger types were the "frégates-vaisseau", with batteries of guns spread over two decks; these were subdivided into two groups; the larger were the "frégates du premier ordre" - or "vaisseau du quatrième rang" (French Fourth Rates) - usually with a lower deck battery of 12-pounder guns, and an upper deck battery of either 8-pounder or 6-pounder guns; and the smaller were the "frégates du deuxième ordre" - or "vaisseau du cinquième rang" (French Fifth Rates) - with a lower deck batter of 8-pounder guns, and an upper deck battery of either 6-pounder or 4-pounder guns. The smaller types were the "frégates légères", with a single battery of (usually) 6-pounder or 4-pounder guns, plus a few small guns on its superstructure or "gaillards".