Trade centres at Ts'ingtao, a town within the bay.
This angle, therefore, divided by the magnifying power of the telescope gives the real angular distance of the centres of a double star.
The principal centres of the system are Buenos Aires, Rosario and Bahia Blanca, with La Plata as a secondary centre to the former, and from these the lines radiate westward and northward.
Thus at the opening of the 17th century, after many adventurous efforts, and the expenditure of many lives and much treasure, the Spaniards found themselves securely established on the river Plate, and had planted a number of centres of trade and colonization in the interior.
Tanning, brick-making, the manufacture of garments, &c., are evenly distributed throughout it, and are to be found in or near all larger centres of population.