sentences:  He was the pioneer in demonstrating the practicability of trade relations by sea between the North Sea countries and the northern portion of Siberia.Beginning his voyages in 1874, he twice reached the Ob River, and five times carried cargoes to the Yenisei River, up which stream he once navigated his ship 2000 miles (3218 km).He facilitated the construction of the Trans-Siberian railway by carrying to that country a large cargo of rails.