 
       
      represents its least power), exact knowledge of the
 ships' courses and of the manner in which they
 would meet or pass each other, if left to their
 own way, could be had while they were still
 three miles apart.
But ships do not commonly meet in straight
 lines, neither do both usually happen to be
 travelling at extreme rates. Their paths cross
 at various angles, wind and weather often retard
 one of the vessels, sometimes both. The Lady
 Bird and Champion, both fast steamers, under
 full steam and sail, were about twenty minutes
 in sight of each other's lights before the collision,
although they were approaching one another
 nearly in a straight line.
But to every hundred collisions that occur in
 the night-time in clear weather, we must add
 forty-five that occur during the day, when the
 men on both ships can actually see their coming
 danger. The air, perhaps, helps to deceive, but
 most eyes on board a ship are misled in estimate
 of the exact course of another vessel that
approaches with a slanting course. Strange vessels
 are so common, distant passing is so common, and,
as compared with everyday experience, collisions
are so rare, that when they do come, they are
 apt to come suddenly, and be quite unexpected.
 The man at the wheel is often the first to give
 alarm. Now, habitual use of the dial, costing
 but a couple of detached minutes for each object,
 would at once show the relation of each ship's
 course, to anything visible upon the face of the
 waters, not to ships only, but to rocks, shoals,
 lighthouses, and points of land.
The manner of using the dial and its
mathematical principle should be described rather in
 a Nautical Magazine than in a popular journal.
 It is a circular brass instrument, marked with
 compass bearings and mile circles, and furnished
 with perforations on which the observer marks
 the position of the two ships at the time of the
 two observations. This is represented in the
 case of the observed ship by a couple of pegs, in
 the case of the observing ship by the centre of
 the plate for the first position, and a peg for the
 second. When the pegs are placed, a couple of
rulers laid along the lines thus indicated, represent
the two ships' courses. The dial is as
 applicable in a crowded channel for observing
simultaneously many ships' courses, as for out at
 sea in marking only one. Distance and speed have
 in every case to be estimated, and enter only as
 probable amounts into the calculation; but as
 to these points, within bounds of sanity, very
 great errors do not affect the truth of the result.
 They do not falsify the courses in the least,
though where the ships would meet if left to
 themselves is where their paths cross, they may
 lead to a wrong, but never dangerously wrong,
 impression of the time of meeting or the point
of crossing.
In the case of lighthouses, or fixed objects,
 Perry's Dial enables mariners to estimate not
 only their bearings, but also their distances,
 within a tenth of a mile. In four years,
between two and three thousand ships and
 steamers have been reported at Lloyd's as lost
 on rocks, shoals, and coasts, through errors in
 navigation alone. Thus the Orion sighted Port
 Patrick Lights for more than an hour before she
 was wrecked on the adjacent coast, through
 miscalculation of distance; and when the Tyne
 was for two hours in sight of the Portland
 Lights, the captain at no time knew his true
 distance from them, and was stranded at last
 under St. Alban's Head.
There is a lack of the testimony of practical
 sailors to the simplicity and certainty of the
 instrument of which we have endeavoured to
 explain the value; but the instrument is new:
 its nature and use were first made public in "A
 brief Treatise on Collisions at Sea and
Shipwrecks," published last year, by Captain Perry,
 at Melbourne, and knowledge of the invention
 only now arrives in England. Its trial is to come
 here, where we trust it will have full consideration,
and find favour according to its merits.
THE MINISTER OF THE INTERIOR.
PORTMANTEAU IN HAND.
Is there any person who has ever jumped into
 a cab, with his portmanteau in his hand and his
face set towards the Straits of Dover, who does
 not prick up his ears at the prospect of any
 proposal which shall in some sort mitigate the
 miseries of the Douane? But if this light and
 comparatively unencumbered personage takes an
interest in this subject, what will be that of
 those husbands and fathers who read this page?
For they, and they alone, can fully understand
 the real difficulties of travelling. 'Tis not alone
the carpet-bag, good reader, nor customary load
of railway wrapper; no, nor the light portmanteau
in the hold that can give the traveller a
 real and powerful interest in the subject of this
 present document. The proprietors of such
 light gear know nothing of the horrors of the
 Douane  but let that pass, they will marry one
 day and take a continental tour, and then, and
 not till then, they will know all about it.
To understand fully the necessity there is for
 some great change in the administration of the
 Custom-house system, it is absolutely necessary
 that a gentleman should be travelling with a
 lady, well provided with luggage, while it is
desirable that he should have, besides, two or three
 children, with their playthings, and a
maidservant who does not approve of the Continent.
 The weather should be intensely and witheringly
 cold, the party should arrive at their destination
 late in the evening, they should have picked up
 so many objects in the course of their travels
that their boxes are all crammed till only by the
 most artful packing can the lids be made to
 close, and they should have borrowed of a
 friend abroad, an immense imperial which used
 to fit on to the back of a travelling carriage,
 and which, being constructed on a slanting
principle to go under the rumble, is unable to stand
 alone, and is always falling heavily backwards
 on official toes, whose owners avenge themselves
 by having it opened.
He, to whom these impedimenta appertain,
 knows the full wretchedness of that shivering
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