The time hitherto occupied by steamers in taking in coals, in almost every place, has constituted of itself a considerable drawback on steam navigation: it may, to a great extent, be avoided. Let carriages, such as are used on the railroads for carrying coals at Newcastle, &c. be constructed with iron handles. These may be made to hold one and a half, or two tons of coals (either of these weights, it is supposed, might be hoisted into a vessel without difficulty), and be all filled and placed on a raft or punt ready at each depot, thirty to sixty in number, according to its importance, awaiting the arrival of the packet steamer. The moment she comes into port, the punt will be alongside, and the whole will be hoisted in in a few hours, the place for receiving them being always, and during the voyage, (p. 006) prepared for them. In this way 120 tons of coals may be taken in within a very short space of time; the buckets first emptied, refilled, and emptied again, to a considerable extent, in a period of no great additional time. At smaller depots and ports, the steamer might hoist in thirty or forty tons of coals during her shorter time of stoppage; and thus steamers, without any material delay, would always have a sufficient and certain supply of fuel. The coals at all the depots should be well covered and protected from the sun. Further, on this head, most of the small coal (the best) which goes to waste at the depots, may be saved by the following simple process:--Let it be mixed with a little clay, considerably diluted, then made into small balls, and afterwards dried in the sun (a rapid process within the tropics), and then taken on board with the others when wanted. It burns with great force. It is so used on estates in the West Indies for Stills. The saving is great, and the labour of making it up exceedingly light. A child may almost perform it. It is necessary to observe, that steam-boats for the torrid zone must be fitted up and out in a manner considerably different, more especially in their hatches, from the best and most splendid boats in this country. For the convenience and health of both the passengers and crews, those for the torrid zone must, in every part, be more roomy and airy, yet so constructed as to be closed in the speediest and securest manner in the event of a hurricane; consequently they will require less expense in building, and fitting up of cabins, &c. than the crack boats in this country, in order to make them so.