But once the _school_ work is over the candidate's real trial begins. Now he finds the value of having attended to his business while at sea and the futility of cramming up seamanship from manuals written for the purpose. For the examiners are all old captains, and the examination is _vivâ voce_. In my own case I followed the usual routine. As soon as I came home I went to a navigation school, or crammer's, and paid my fee, not imagining that I should learn anything, but expecting to have what I did know marshalled in the most useful order. I afterwards found that I need not have spent my money. I can honestly declare that in my case, at any rate, I got no good whatever. Indeed, I got a certain amount of harm, which, however, did no damage beyond making a bit of fun, as it happened. One of the last things my crammer did was to test my sight for colour-blindness. It was the first I had ever heard of such a thing; and when he held up various squares of coloured glass between me and the light, I named them promptly according to their shades, having a very keen and acute eye for colour. To my petrified amazement he suddenly slammed the glass into the box he was holding, and said, "You are absolutely colour-blind. Whatever do you mean by inventing all those names for these glasses? There are only two colours here, red and green; the others are white and black." I promptly selected a glaring gamboge glass and asked him what _that_ was. He said, "Green." A bright purple puzzled him for a moment, but was then cheerfully pronounced green also! Secretly I felt sure that there was a blunder somewhere, but I had long learned not to argue with those in authority, so I said resignedly, "Well, I suppose I must take my chance." But I confess I felt very uncomfortable. Then he brought out an amazing diagram of his own invention for teaching the "rule of the road." I had seen the thing before, but carefully avoided having anything to do with it. I felt sure that I knew the rule of the road in actual practice, as well as all the articles, by heart, and the late Thomas Gray's admirable rhymes, and I didn't propose being worried by any old diagrams. However, he insisted, so with a sigh I submitted. And before ten minutes he solemnly assured me that I was a hopeless ass to think of going before the examiners at all; that I didn't know the first little thing about the rule of the road, which was the most important part of the examination, and that my only hope was to go home and sweat it up. As if any man could learn the rule of the road for practical use out of a book ashore! I didn't say anything, but as soon as I got outside I dismissed him and all his discomforting remarks from my mind entirely, amusing myself in various ways unconnected with either navigation or seamanship until bedtime.