CREATE TABLE table_12778 ("Name" TEXT, "Location" TEXT, "Land" TEXT, "Longest span in s metre  (  feet  ) " TEXT, "Arch type" TEXT, "Completed" TEXT)

What kind of arch is the pont de montanges (pont-des-pierres)?
SELECT "Arch type" FROM table_12778 WHERE "Name" = 'pont de montanges (pont-des-pierres)'
SELECT "Arch type" FROM "table_12778" WHERE "Name" = 'pont de montanges (pont-des-pierres)'