The further back in time one goes, the broader the signals used become.

As a result, books published between these two dates show the signal using the wrong flags.

A signal used to establish and to maintain the same color relationships that are transmitted.

Some signals use two or three colors in tandem.

The two drivers communicated by signals using the engine whistles.

A position-light signal used a large round target with an array of up to nine lights.

From this information, a good rule of thumb is that signal using optical fiber for communication will travel at around 200,000 kilometers per second.

Generally used for signals use, three were used as armoured cars in Finland.

The signal to refer a matter is using both hands to mime a TV screen by making a box shape.

Today, a single distant signal is generally used which displays caution if speed reduction is necessary.