The great majority of _-culum_ words[186] also are concrete. They may be grouped into three classes as far as their verb stems are concerned: (1) Those denoting instrument; (2) Those denoting place; (3) Those denoting the object of the action expressed by their verb stems. 1. NOUNS DENOTING INSTRUMENT.--Adminiculum (ad-manus) is properly anything on which the hand may rest, but the examples show it meaning regularly a prop, or support, both concretely and figuratively: adminiculorum ordines me delectant, capitum iugatio, religatio vitium, C. 53; natura semper ad aliquod tamquam adminiculum adnititur, Lael. 88. Baculum (etymology very uncertain, but probably same root as seen in βαίνω) from its verb stem, should mean only a walking stick, but it is applied to almost any kind of staff or sceptre: proximus lictor converso baculo oculos misero tundere vehementissime coepit, Verr. 5, 142; baculum aureum regis berylli distinguebant, Curt. 9, 1, 30. Everriculum (everro) is a sweep net (also used figuratively): neque everriculo in litus educere possent, Varr. R. R. 3, 17, 7; quod umquam huiusmodi everriculum ulla in provincia fuit?, Verr. 4, 5, 3. Ferculum (fero) is that on which anything is carried: spolia ducis hostium caesi suspensa fabricato ad id apte ferculo gerens in Capitolium ascendit, Liv. 1, 10, 5; ubi multa de magna superessent fercula cena, Hor. S. 2, 6, 104. Gubernaculum (guberno) is an instrument for guiding: piscium meatus gubernaculi modo regunt caudae, Plin. 11, 50, 111; hic ille naufragus ad gubernaculum accessit, et navi, quod potuit, est opitulatus, Inv. 2, 154. Incerniculum (incerno) is an instrument for sifting, a sieve; it occurs only twice, and it is difficult to see how it differs from another noun on the same stem, cribrum: opus est incerniculum unum, cribrum unum, Cato, R. R. 13; Athenienses decretum fecere, ne frumentarii negotiatores ab incerniculis eum [mulum] arcerent, Plin. 8, 44, 69. In the latter example the incernicula are the vessels in which bran, sifted from the flour, was set up for sale. Operculum (operio) like operimentum is an instrument for covering: aspera arteria tegitur quodam quasi operculo quod ob eam causam datum est, ne spiritus impediretur, N. II, 136; operculum in dolium imponito, Cato, R. R. 104. Perpendiculum (perpendo) is a plumb line, but is found most frequently with _ad_ forming an adverbial phrase meaning perpendicularly: non egeremus perpendiculis, non normis, non regulis, Cic. A. fr. 8; tigna non directa ad perpendiculum, sed prone et fastigate, B. G. 4, 17. Piaculum is a means of appeasing, an offering; perhaps also the appeasing itself; and the act requiring expiation: decrevit habendas triduum ferias, et porco femina piaculum pati, Leg. 2, 22; nonne in mentem venit quantum piaculi committatur? Liv. 5, 52; duc nigras pecudes: ea prima piacula sunto, Aen. 6, 153.