‘These youngsters think too much of their ease,’ said Jack. ‘They are nothing but a parcel of helots.’
‘Pray have helots a particular nautical signification, like dogs, mice, fishes and so on?’ asked Stephen.
‘Oh no, just the ordinary sense of idle young devils, you know – limbs of Satan. I must stir them up, and make their lives a misery.’

This is more like it. I was vaguely under the impression that this came next in the series after Desolation Island