upon the road to sea power which never since has been relaxed.  To him were due the measures—­not, perhaps, economically the wisest, judged by modern lights, but more than justified by the conditions of his times—­which drew into English hands the carrying trade of the world.  The glories of the British navy as an organized force date also from his short rule; and it was he who, in 1655, laid a firm basis for the development of the country’s sea power in the Caribbean, by the conquest of Jamaica, from a military standpoint the most decisive of all single positions in that sea for the control of the Isthmus.  It is true that the successful attempt upon this island resulted from the failure of the leaders to accomplish Cromwell’s more immediate purpose of reducing Santo Domingo,—­that in so far the particular fortunate issue was of the nature of an accident; but this fact serves only to illustrate more emphatically that, when a general line of policy, whether military or political, is correctly chosen upon sound principles, incidental misfortunes or disappointments do not frustrate the conception.  The sagacious, far-seeing motive, which prompted Cromwell’s movement against the West Indian possessions of Spain, was to contest the latter’s claim to the monopoly of that wealthy region; and he looked upon British extension in the islands as simply a stepping-stone to control upon the adjacent continent.  It is a singular commentary upon the blindness of historians to the true secret of Great Britain’s rise among the nations, and of the eminent position she so long has held, that writers so far removed from each other in time and characteristics as Hume and the late J.R.  Green should detect in this far-reaching effort of the Protector, only the dulled vision of “a conservative and unspeculative temper misled by the strength of religious enthusiasm.”  “A statesman of wise political genius,” according to them, would have fastened his eyes rather upon the growing power of France, “and discerned the beginning of that great struggle for supremacy” which was fought out under Louis XIV.  But to do so would have been only to repeat, by anticipation, the fatal error of that great monarch, which forever forfeited for France the control of the seas, in which the surest prosperity of nations is to be found; a mistake, also, far more ruinous to the island kingdom than it was to her continental rival, bitter though the fruits thereof have been to the latter.  Hallam, with clearer insight, says:  “When Cromwell declared against Spain, and attacked her West Indian possessions, there was little pretence, certainly, of justice, but not by any means, as I conceive, the impolicy sometimes charged against him.  So auspicious was his star, that the very failure of that expedition obtained a more advantageous possession for England than all the triumphs of her former kings.”  Most true; but because his star was despatched in the right direction to look for fortune,—­by sea, not by land.