PLOESCI (Ploescii)  , the capital of the department of Prahova, Rumania; at the southern entrance of a valley among the Carpathian foothills, through which flows the river Prahova; and at the junction of railways to Buzeu, Bucharest and Hermannstadt in Transylvania . Pop . (1goo), 42,687 . As the name Ploesci (pluviena, rainy) implies, the climate is moist . The surrounding hills are rich in petroleum, salt and lignite . There are cardboard factories, roperies, tanneries and oil mills . Ploesci possesses schools of commerce and of arts and crafts, several banks, and many synagogues and churches, including the Orthodox church of St Mary, built in 1940 by Matthew Bassarab .