their danger.

The lookout on board instantly sang out, "Starboard har-r-r-d-! beacon
ahead!" and Ruby looked up in surprise, just as the _Smeaton_ emerged
like a phantom-ship out of the fog. Her sails fluttered as she came up
to the wind, and the crew were seen hurrying to and fro in much alarm.

Mr Stevenson himself stood on the quarterdeck of the little vessel, and
waved his hand to assure those on the beacon that they had sheered off
in time, and were safe.

This incident tended to strengthen the engineer in his opinion that the
two large bells which were being cast for the lighthouse, to be rung by
the machinery of the revolving light, would be of great utility in foggy
weather.

While the _Smeaton_ was turning away, as if with a graceful bow to the
men on the rock, Ruby shouted:

"There are letters here for you, sir."

The mate of the vessel called out at once, "Send them off in the
shore-boat; we'll lay-to."

No time was to be lost, for if the _Smeaton_ should get involved in the
fog it might be very difficult to find her; so Ruby at once ran for the
letters, and, hailing the shore-boat which lay quite close at hand,
jumped into it and pushed off.

They boarded the _Smeaton_ without difficulty and delivered the letters.

Instead of returning to the beacon, however, Ruby was ordered to hold
himself in readiness to go to Arbroath in the shore-boat with a letter
from Mr Stevenson to the superintendent of the workyard.

"You can go up and see your friends in the town, if you choose," said
the engineer, "but be sure to return by tomorrow's forenoon tide. We
cannot dispense with your services longer than a few hours, my lad, so I
shall expect you to make no unnecessary delay."

"You may depend upon me, sir," said Ruby, touching his cap, as he turned
away and leaped into the boat.

A light breeze was now blowing, so that the sails could be used. In
less than a quarter of an hour sloop and beacon were lost in the fog,
and Ruby steered for the harbour of Arbroath, overjoyed at this
unexpected and happy turn of events, which gave him an opportunity of
solving the mystery of the letters, and of once more seeing the sweet
face of Minnie Gray.

But an incident occurred which delayed these desirable ends, and utterly
changed the current of Ruby's fortunes for a time.

CHAPTER TWENTY SIX.

A SUDDEN AND TREMENDOUS CHANGE IN RUBY'S FORTUNES.

What a variety of appropriate aphorisms there are to express