ry different; and supposing that the boy sent aloft to
watch for the light were to report 253 instead of 243, without waiting
to correct his view, the captain, by turning to his book, would
perhaps find that No. 253 was in the Straits of Sunda, or some equally
remote situation, and would easily recognise the error. When we take
into account the number of vessels lost by mistaking one lighthouse
for another, the value of this proposal becomes apparent. Mr Babbage
shews, that bell-strokes might be employed to announce the number of a
beacon in foggy weather; and he believes that the time is not far
distant when buoys will also be indicated by a light. Now that
lighthouse dues are to be reduced one-half, we may hope to see
improvement in more ways than one.

This is but a small part of what promises more and more to become a
great question--that of navigation. It is felt that, in these go-ahead
days, we must be paying not less attention to our maritime than to our
inland arm of commerce; and this has brought the question of wood
_versus_ iron ships again into prominent notice. The advocates of iron
shew that the dry-rot, so destructive to wood, cannot enter metal;
that lightness and speed, those prime essentials, are insured by the
use of iron; that iron ships are safer, more easily repaired, and
cheaper than vessels built of wood; and that they are more lasting.
The chief objection hitherto has been the liability of iron to become
foul in tropical climates; but this now appears to be in a measure
overcome. According to Mr Lindsay: 'An admixture has been applied,
termed "Anti-Sargassian Paint," which has been found to answer the
purpose better than any yet discovered. From the experience of its
properties, we cannot say that in itself it is yet sufficient; but it
appears a fair substitute till some other preparation is discovered. A
gentleman at Glasgow,' he adds, 'has already discovered a compound,
which, being mixed in a fluid state with the iron, is expected to
answer the desired purpose. There is another disadvantage which will
soon be overcome--the greater liability to error in the compasses of
iron ships; an error which, however, also occurs, though perhaps to a
less extent, in every wooden ship. By a most ingenious invention,
which will shortly be made public, such errors in any ships, under any
circumstances, can at all times be at once detected.'

An important patented process for producing tapered iron, has been