Why did early carriers use longitudinal wires?

What purpose did longitudinal arrestor wires serve on early aircraft carriers?

They were intended to keep an aircraft from tipping or sliding over the deck edge, unlike transverse wires that arrest its forward motion.

Longitudinal wires ran along the flight deck rather than across the landing path. Their purpose was not principally to stop an aircraft's forward travel. Instead, they helped keep a landing aircraft from tipping or sliding over the side. The distinction explains why early carrier photographs can show wire layouts unlike modern transverse arresting gear.