As soon as the green signal-man has created this sensation among bipeds and quadrupeds, taking with him the three flags, of danger (red), caution (green), and security (white), he proceeds down the line a few yards to a point from which he can plainly see his brother signal-man stationed at the mouth of the Euston tunnel. If any obstruction exists in that direction, the waving of the red flag informs him of it; and it is not until the white one from the tunnel as well as that from the station-master on the platform have reported to him that “all is clear” that he returns to his important but humble office (12 feet in length by 9 in breadth) to announce, by means of his compressed-air apparatus, this intelligence to the ticket-collector at Camden Station, whose strict orders are, on no account whatever to allow a train to leave his platform until he has received through the air-pipes, from the signal-office at Euston Station, the Company’s lugubrious authority to do so. In the latter office there are also the dial and wires of an electric telegraph, at present inoperative. The signal-man, however, mentioned to us the following trifling anecdote, as illustrative of the practical utility of that wonderful invention, which has so justly immortalized the names of Cooke and Wheatstone. An old general officer, who, from his residence some miles beyond Manchester, had come up to Euston Station on an invitation from the East-India Directors to be present at the dinner to be given by them to Lord Hardinge, found on his arrival that it would be necessary he should appear in regimentals: and the veteran, nothing daunted, was proposing to return to Manchester, when the signal-man at Euston advised him to apply for them by electric telegraph. He did so. The application, at the ordinary rate of 280,000 miles (about twelve times the circumference of the earth) _per second_, flew to Manchester; in obedience to its commands a porter was instantly despatched into the country for the clothes, which, being forwarded by the express train, arrived in abundant time for the dinner. The charge for telegraph and porter was 13_s._ 8_d._