of the British merchant; for you are now standing on the lower steps of a ladder, which, when it is mounted with diligence and circumspection, leads always to respectability, not unfrequently to high honour and distinction.  Bear in mind, then, that the quality which ought chiefly to distinguish those who aspire to exercise a controlling and directing influence in any department of human action, from those who have only a subordinate part to play, is the knowledge of principles and general laws.  A few examples will make the truth of this proposition apparent to you.  Take, for instance, the case of the builder.  The mason and carpenter must know how to hew the stone and square the timber, and follow out faithfully the working plan placed in their hands.  But the architect must know much more than this; he must be acquainted with the principles of proportion and form; he must know the laws which regulate the distribution of heat, light, and air, in order that he may give to each part of a complicated structure its due share of these advantages, and combine the multifarious details into a consistent whole.  Take again the case of the seaman.  It is enough for the steersman that he watch certain symptoms in the sky and on the waves; that he note the shifting of the wind and compass, and attend to certain precise rules which have been given him for his guidance.  But the master of the ship, if he be fit for his situation—­and I am sorry to say that many undertake the duties of that responsible office who are not fit for it—­must be thoroughly acquainted, not only with the map of the earth and heavens, but he must know also all that science has revealed of some of the most subtle of the operations of nature; he must understand, as far as man can yet discover them, what are the laws which regulate the movements of the currents, the direction of the tempest, and the meanderings of the magnetic fluid.  Or, to take a case with which you are more familiar—­that of the merchant.  The merchant’s clerk must understand book-keeping and double-entry, and know how to arrange every item of the account under its proper head, and how to balance the whole correctly.  But the head of the establishment must be acquainted, in addition to this, with the laws which regulate the exchanges, with the principles that affect the production and distribution of national wealth, and therefore with those social and political causes which are ever and anon at work to disturb calculations, which would have been accurate enough for quiet times, but which are insufficient for others.  I think, therefore, that I have established the truth of the proposition, that men who aspire to exercise a directing and controlling influence in any pursuit or business, should be distinguished by a knowledge of principles and general laws.  But it is in the acquisition of this knowledge, and more especially in its application to the occurrences of daily life, that the chief necessity arises for the