Except for a small tribute in the shape of fish food and certain salts th_cean is to-day almost a dead loss to the world, and what is worse, th_reatest of all obstacles to progress. It separates us from our kin, wreck_ur ships, claims a yearly toll of dead, and is barren, fruitless, a mer_eceptacle for garbage. A hundred years hence we shall have awakened to thes_acts and found means to make "the caverns vast of ocean old" something bette_han a subject for the poet and a resting-place for the dead whom it murders.
Not every dream, however, can be realised— not even the engineer's. Some year_go certain ardent spirits in France announced that the desert of Sahara la_elow the level of the sea and could be flooded with the Atlantic o_editerranean. The effect of this, it was considered, would not merely be t_nconvenience certain Arabs, but to change entirely the climate of the rest o_quatorial Africa. Laved by the beneficent waves of ocean, lands at presen_ninhabitable would, it was declared, become fertile and salubrious. Th_roject was dismissed or shelved as impracticable from engineerin_ifficulties. Shall we, a hundred years hence, have met these difficulties ?
Probably not. To work such changes in the distribution of land and water wil_e a thing not indeed beyond the power of the next century's engineers, bu_eyond their daring. The accomplishment of them might, if at all rapid, b_ttended by frightful disasters, some of which can be readily estimated, bu_f which the worst would probably remain unforeseen and unimaorined until th_rrevocable moment of fulfilment. To increase to this extent the area of th_orld's oceans, without increasing (as of course we could not increase) thei_ass, would perceptibly lower the level of the sea everywhere, and i_ccordance with the well-known hydrostatic law things would " right themselves
" on a cataclysmal scale. Every narrow strait in the world, every oceani_anal would become, for the time being, a roaring cataract. The Mediterranea_ould rush tumultuously out through the Straits of Gibraltar and the Sue_anal, and the overflow would flood the adjacent lands. The Straits of Dove_ould roar like Niagara, and all Kent, and the low-lying north-east corner o_rance, would be devastated. The isthmus of Panama might at the same time b_wept away, for the narrow banks of the completed Panama Canal would certainl_ive way before the weight of the two oceans. All the rivers of the worl_ould rush down in spate until they ran nearly dry from the increased outfall.
The sea would recede from all the coasts. Along- with this fall in the leve_f the sea would come tempests such as, since the appearance of man on th_lanet, the world has never known. For the sea-supported atmosphere would suc_nto its vacuum the whole weight of the over-lying air until pressure wa_qualised. And the climate of all the world would be reconstituted in new an_robably inconvenient ways.
No. We cannot venture thus to change the face of creation. What we can an_hall do is to make the best of it. In a hundred years' time many countries a_resent undeveloped will be rich and populous. Canada, for one example, has a_rea greater than that of the United States, with a population smaller tha_he population of Greater London. And Canada, endowed as it is with almos_very source of wealth, will before long become perhaps the richest country i_he world. By this time next century it will also be one of the most populous.
Siberia, again, with many fertile and salubrious tracts, will certainly hav_een more intelligently utilised than by making a vast prison of it. But whe_ll the regions available for human habitation are populated and made use of,
the centres of civilisation will probably lie very much where they lie now ;
and here the congested populations will have found that they can no longe_olerate the waste of a neglected ocean. As we push outward from the centre o_he continents, the seaboard will have to be utilised and extended. There i_othing to daunt the engineers of a hundred years hence in the project o_recting on the sea a vast floating city, fully as convenient as the presen_ities of terra firma, and, while vastly more healthful, quite substantia_nough to resist storm and every motion of the sea, except the tides on whic_he city will rise and fall—tides which will no doubt furnish the motive powe_f many conveniences in ocean cities.
There are great advantages in a city thus founded, as compared with those w_t present inhabit; and we certainly shall not be able to neglect them. Ther_ill be no particular reason for economy of space or for insalubriou_vercrowding (since the sea has no landlord), and breadth would make fo_tability as well as for convenience. Urban traffic will employ an entirel_ew light vehicle, the skimmer. It has been mentioned as a thing beyond doub_hat the ships of a hundred years hence will no longer float in the sea, bu_ide on its surface, thus evading both the instability and the resistance a_resent so troublesome to marine engineers. As soon as the necessity-arise_or providing street traffic in the ocean city—when " the sea is in the broad,
the narrow streets, ebbing and flowing, and the salt weed cHngs to the marbl_f her palaces " —invention will meet the demand, and light street waggons an_arriages will everywhere glide about, performing the daily needs of th_nhabitants. Something in the nature of breakwaters will provide against wave-
play and form an unequalled exterior boulevard; and by means of an inventio_hich will long since have been called for by the requirements of othe_ocalities, the air of dwelling-houses in the ocean city will be wholesomel_reed from damp.
For we shall certainly not have failed to act upon our knowledge of the fac_hat irregularities in the proportion of atmospheric moisture are responsibl_or the unhealthiness of certain areas ; and we shall have learned, by mean_f the anhydrator, to provide any place with exactly the degree of damp o_ryness necessary to health. The same apparatus, by desiccating the air to th_xtreme point, will keep the houses of an ocean city dry and thus do away wit_n objection which would make homes built on the water insufferable to-day.
If we have not wholly reformed throughout the world our system of land tenure,
the conquered ocean will unquestionably relieve the tension which is create_y it, and perhaps a radical change of this character will only becom_ossible when the enormous advantages of it have been practically exemplified.
But there is another way in which the conquest of ocean ought to prove a grea_conomic boon to the world. Except in the case of a few coal mines, wit_hafts sunk near the sea beach, we have hardly at all besfun to investig'at_he contents of the ocean floor. There is, so far as I am aware, no particula_eason to doubt that the constitution of the subterranean world is in mos_espects very much the same under the sea as under the land. Probably vas_iches, as yet undreamed of, lie below the surface of the ocean and beneat_ts floor. There can be no question that the needs of the world will make u_ager to tap them, as we should already have begun to, if any way could b_iscovered of overcoming the engineering difficulties involved. Thes_ifificulties, in the present state of our knowledge, may well appal th_toutest imagination. The problem presented by the immense and paralysing ai_ressure in a mine at this great depth would have to be overcome. Even in som_reat terrestrial excavations already made the problem occurs : and where (a_n river tunnels and elsewhere) men attempt to work in great air-pressure_rtificially induced, the phenomenon called caisson-disease occasion_ractical difficulty. But the mere fact of an achievement being almos_nconceivable in the light of present knowledge and invention must not b_llowed to put a clog upon a forecast of what next century may attain. It is _ypothesis which the reader has been invited to accept, not merely tha_iscovery and invention will go on, but that they will go at a constantly-
increasing pace. We must not, therefore, allow what may well seem, at th_resent day, insuperable engineering difficulties to forbid the belief tha_he undiscovered wealth of the earth below the sea will be tapped for th_enefit of the new age. What minerals may lie there, a rich heirloom for th_oming time, we can but roughly imagine. But enterprise and the world'_ecessities will spur us on to search them out, until the new people, derivin_ike a fresh Antaeus constant stores of strength from Mother Earth, will ente_nto possessions which must vastly relieve their necessities. Individua_nterprise will solve the problems and reap its store of profits. But th_cean is no-man's land, and the people—perhaps a world-people, for thi_urpose at least not subdivided into antagonistic communities—will beyon_oubt take toll, for the relief of general taxation, from the earnings of th_ew mineralogy.
In other ways, too, the sea itself will be made use of. We shall get our sal_rom it, the process of separation being electrolytic. Fish will probably b_aten later than any other form of animal food. But the chief gift of the se_o the life of the future will be the two gases of which water is composed—
oxygen and hydrogen: and the other gas, chlorine, which forms half the salt,
as well as the metal sodium which forms the other half, will probably hav_any new uses found for them. Liquefied oxygen will no doubt be our sol_isinfectant. It will also replace the poisonous, noisome and destructiv_leaching agents used to-day. Hydrogen, the lightest of all gases, will b_nother staple of commerce. It will (as we have elsewhere seen) probably b_he only fuel employed, for its combustion furnishes the greatest hea_errestrially known, and its flame is smokeless and yields no poisonous by-
product. Moreover, the evaporation of liquid hydrogen, by a sort of curiou_evenge, produces the greatest available cold. If anything in the nature o_alloons should survive the century hydrogen will inflate them, and both ou_ydrogen and our oxygen will most likely be got by preference from the sea.
There are many reasons for this preference. Probably there will be som_dvantage in the matter of expense, since the salts of ocean water would be _y-product of the operation, and it is conceivable that a use may be found fo_he rarer among them, which could only be obtained in satisfactory quantitie_y reducing to dryness huge amounts of water. And potable or spring water_ill perhaps be too precious a commodity to be consumed unnecessarily.
Distilled water could no doubt be used for drinking purposes, and bacterio-
logically it is of course unexceptionable; but there are certain objections t_t, and though these may doubtless be overcome, natural waters have a valu_hich cannot be ignored.
Thus the oceans of the world, as yet mere watery deserts, useful to hardly _alculable percentage of the people (and then only at the expense of the rest)
will have become the world's inheritance, and its hoarded wealth will stav_ff the time—whose coming we must not ignore—when our world-capital begins t_e exhausted. For that time must come. We are living upon the hoards which th_omb of our mother the earth has borne to our father the sun. But our mothe_s, in respect at all events of mineral wealth, past the age of conception ;
and every century brings us more rapidly near to the time when we shall, lik_pendthrifts, have lived out our capital. Already the end of coal is in sight.
When, at the end of a vista however long, we begin to be able to foresee th_xhaustion of other minerals, we shall face a problem appalling in its nature.
Perhaps before our store of heat gives out and reduces earth to the state of _ead world Hke the moon, we shall already have exhausted our stock. N_conomies in the use of scrap metal and the re-employment of the material o_achines which have been superseded can save us from ultimate metalli_ankruptcy in a future calculated perhaps in thousands (but not man_housands) of years. Our only succour seems to lie in a conception for which
(despite the efforts of some lively thinkers who have been obliged to ignor_ll but the least important difficulties of the subject) we have n_aterial—the conception of means by which the cold depths of interplanetar_pace may be traversed. Even if we allow imagination, untrammelled by the mos_vident necessities of the case, to suggest a speed of transport computabl_nly by astronomical analotjies, we still lagr behind anything which coul_erve this purpose, unless we concurrently believe that human life shall, b_hat time, be lengthened into centuries. Otherwise, however recklessly we ma_onceive of speed in interplanetary travel, man would almost require to liv_or many centuries in order to reach and return from any destination whic_ould not inevitably destroy him by fire or cold when he arrived at it. Mos_ikely man is for ever destined to accept the bounds of his own planet, and t_e limited by its resources. In order that these resources may be utilised t_he uttermost of his needs, the contents of the ocean floor must undoubtedl_e laid under contribution, and probably we shall not antedate thi_chievement if we consider that it will have been at least entered upon _undred years hence.