CREATE TABLE table_6446 ("Name" CLOB, "Pinnacle height" CLOB, "Structural type" CLOB, "Main use" CLOB, "Country" CLOB, "Town" CLOB)

What is the Main use of emley moor tower (mk.3)?
SELECT "Main use" FROM table_6446 WHERE "Name" = 'emley moor tower (mk.3)'
SELECT "Main use" FROM "table_6446" WHERE "Name" = 'emley moor tower (mk.3)'