Part 96

Below we see the most modern types of Morse instruments. In the center is the key, which is not much changed except that it is built to be low down to a table, so that the operator may rest his forearm on the table top in front of it, and operate the key with his wrist, with less fatigue. The relay at the left is interesting. It shows how little this instrument has changed, except for refinement in its appearance, from the first relay built by Professor Morse. At the right is the Morse sounder, which has replaced the old Morse tape recording instrument. When current goes through the magnets they attract a piece of iron attached to the metal arm and pull it down to strike the brass frame. This makes a click, and when the current is intercepted, the magnets release the arm and a spring pulls it back, making another click. The operator reads the message by listening to the clicks. If the up click comes right after the down click it represents a dot. If there is a pause between them, a dash is represented.]

Relay

Key

Sounder

MODERN MORSE INSTRUMENTS]

Light Intermediate

Heavy Intermediate

Main Cable

Rock Cable

Heavy Shore End

Rock Cable

Heavy Shore End

Heavy Intermediate

Light Intermediate

Deep Sea

Bay Cable

FIG. 1.--CABLES ON VANCOUVER-FANNING ISLAND SECTION.

Full size.

Core, 600/340.]

Yarn Serving & Compound

16 No. 13 (·095) Galvanized Wires

Jute Serving

Gutta Percha

Copper Conductor

FIG. 2.--CABLES USED ON FIJI-NORFOLK ISLAND-QUEENSLAND AND NEW ZEALAND SECTIONS. Full size. Core 130/130.

This picture shows cross-sections of a cable which runs from Vancouver, B. C., to Australia and New Zealand. A cable is not laid with a uniform cross-section. On the floor of the ocean, perhaps miles below the surface, the cable rests quietly and is not moved by storms which generate great waves on the surface of the water. As the cable approaches the shore, the movement of the water goes deeper and the cable must be made heavier to prevent it from being worn by movement on the bed of the ocean. Where the cable passes over a rocky bottom, it is made much larger in diameter and is heavily armored.]

The Story in an Ocean Cable

What is a Cable Made of?