TO THE RIGHT HON.

CHARLES JENKINSON, Esq.

SECRETARY AT WAR, AND

ONE OF HIS MAJESTY'S MOST HONOURABLE PRIVY COUNCIL.

SIR,

IF I ask leave to inscribe the following work to your name, it is with an honest desire of taking the only opportunity in my power to discharge a very small part of a just debt; and an author, who is venturing upon a new path of science, may be excused if he wishes to be introduced to the world under the auspices of some powerful friend, who has acquired more fame, and is entitled to more respect than himself.

To

To the honour which you derive from the rank and antiquity of your Family, and your own many excellent qualifications, His Majesty has been pleased to add that of one of the highest offices in this kingdom; and you have reflected honour upon your office by a faithful and diligent execution of the duties belonging to it, As an Englishman, and a lover of my country, I think myself under obligations to you for your public services to it at this critical time, when able heads and busy hands are so necessary to its preservation.

All men are witnesses to the honours

of your riper years, in which you have passed through almost every department of the State; but it was my lot, Sir, to be a witness to the prudence of your youth. While others of your own age were wasting their health, their fortunes, and their precious hours upon idle and corrupting amusements, you were busy

in the cultivation of a strong and fruitful mind: you never lost sight of the great objects of your education, but improved your talents by an unwearied application to every branch of useful and ornamental learning, and prepared yourself for rendering to your country those eminent services, of which we are now reaping the advantage. I have observed, not without some wonder, that in an age when calumny is become a traffick, and official dignity is thought to be synonymous with guilt, it has been your peculiar felicity to stand uncensured, as if you were suspected to be invulnerable.

Perhaps I may seem to be in need of an apology for presenting to a Gentleman engaged in the duties of the War-office, a Treatise on Philosophy; a study more nearly related to the gown than to the sword; but I need not remind you, Sir, that Philosophy is a mistress of arms as

well as of arts; that the whole business of war in these latter ages has chiefly turned on the various applications of a philosophical experiment; and that of two commanders who have equal courage, he will be the best soldier who is the best philosopher.

That you may have leisure for every kind of literary recreation, when the Divine Providence shall have conducted us (as we trust it will) through the dangers of a necessary war, to the blessings of an. honourable peace, is the wish and prayer of,