The currents of air that the walls of the ship direct upwards, as well as in the line of its course...

[Anon Oby]

"The currents of air that the walls of the ship direct upwards, as well as in the line of its course are enough to give the the great bird with its immense wings sufficient sustenance and progress."

I am confused by the green part. I do know it's the subject in this sentence. But the confusion is, I have no idea what the green part is talking about.

Source: A Countryman's Creed by William Beach Thomas

 

[emsr2d2]

"The currents of air that the walls of the ship direct upwards, as well as in the line of its course are enough to give the the great bird with its immense wings sufficient sustenance and progress."

Source: "A Countryman's Creed" by William Beach Thomas

I am confused by the green part. I do know it's the subject in this sentence no full stop here but the confusion is, I have no idea what the green part is talking about means.

Note my changes above. I've put your whole post in the default font and size. Please do this yourself in future. The source information should appear directly after the quoted text. Remember to mark out titles in some way. I've put it in quotation marks. You could put it in italics.

In my opinion, there should be a comma after "course". Aside from that, though, would you find it easier to understand if the part between commas were removed, leaving the following?

The current of air that the walls of the ship direct upwards are enough to give the great bird ...

 

[Tarheel]

I've never heard of immense wings before.

 

[emsr2d2]

I've never heard of immense wings before.

Don't you think an albatross, for example, has really huge wings?

 

[stanislaw.masny]

Not a teacher.

The currents of air that the walls of the ship direct upwards"
In my opinion, this is about a bulkhead, an upright wall within a ship's hull.

 

[emsr2d2]

Not a teacher.

The currents of air that the walls of the ship direct upwards"
In my opinion, this is about a bulkhead, an upright wall within a ship's hull.

How would a wall inside a ship's hull direct currents of air upwards? For a bird to take advantage of currents of air, those currents must be outside.

 

[Tarheel]

Don't you think an albatross, for example, has really huge wings?

It's a big bird. The wings of an albatross are right for it.

 

[stanislaw.masny]

I thought the hull consisted of inner and outer walls. Air currents are created near the external walls.

P.S. Sir William Beach Thomas spent time at sea and may have seen large-winged seabirds such as albatrosses.

 

[Tarheel]

My guess is that we're talking about ships, but I don't know why a ship would have wings.

 

[kttlt]

Not a teacher.

My guess is that we're talking about ships, but I don't know why a ship would have wings.

I don't think "the great bird" is a figurative way of describing the ship there, it's talking about some actual bird (with immense wings) drifting alongside the ship, supported by the air currents produced by its movement.