He attempted to befriend his friend till he found that it was impossible, and then, with the best grace in the world, accepted the official nominee that was offered to him.
It may be said that had Thackeray succeeded in that attempt he would surely have ruined himself.

No man can be fit for the management and performance of special work who has learned nothing of it before his thirty-seventh year; and no man could have been less so than Thackeray.
There are men who, though they be not fit, are disposed to learn their lesson and make themselves as fit as possible.

Such cannot be said to have been the case with this man.

For the special duties which he would have been called upon to perform, consisting to a great extent of the maintenance of discipline over a large body of men, training is required, and the service would have suffered for awhile under any untried elderly tiro.

Another man might have put himself into harness.
Thackeray never would have done so.