There were quite a few steamship lines crossing the Atlantic in the 19th century.
Signals of the Steamers Sailing between North- America and Europe. aug 1870
WE find the following interesting facts on this subject in one of our German contemporaries:
CUNARD LINE—Two rockets and a blue light.
INMAN LINE—A blue light at the bow, a red one in the centre, a blue light at the stern, and two rockets. The lights all burn at the same time.
GUYON LINE—Blue lights at tile bow, centre, and the stern, all burning simultaneously
NATIONAL LINE—A blue light, a rocket, and a red light
ANCHOR LINE—Alternately red and white lights.
MONTREAL OCEAN STEAMSHIP COMPANY (PORTLAND LINE.)—White and red rockets following each other.
FRENCH LINE—A blue light at the bow, a white one amidship, and a red one at the stern, all burning simultaneously.
NORTH-GERMAN LLOYD (BREMEN.)—A blue light at the bow, and one at the stern, and two rockets.
HAMBURG-AMERICAN PACKET LINE—A roman light, a rocket, and again a roman light, following each other at an interval of about three minutes.
NEW-YORK AND LONDON LINE—A rocket, a blue light, and again a rocket. RUDGERS LINe—A blue and a red light in the centre, both burning simultaneously.
In the day-time these steamers may be recognized by the color of their smoke-stacks. These are painted respectively: Red, with black top; black, with a white stripe and black top; black, with a red stripe and a small black top; white, with black top ; entirely black black alternating with white; red and white stripes amid a black top; red with black top; black; black; white; finally, those of the Rudgers steamers are black, and the paddle-boxes are all painted white.