Map symbols for bridges and river related features on Latvian topographic maps of the 1920s and earlier. From the book
Apzimejumi Merniecibas un Kulturtechniskiem Planiem
(Legends from Surveying and Cultural-Technical Plans)
Ministry of Agriculture
Riga, Latvia, 1928.
Original plate with translation to English below:
Boundary in the middle of the river
Boundary at the edge of the drainage ditch