"You have learned as much, in one morning, as many of the boys who attend schools would learn in a month," he said. "If you go on like this, I will warrant that, if Percy delays his return for two months, you will know as much as many who have been two years at the work. I have always said that it is a mistake to teach children young; their minds do not take in what you say to them. You may beat it into them, but they only get it by rote; and painfully, because they don't understand how one thing leads to another, and it is their memory only, and not their minds, that are at work." The next day came news that the Scotch had crossed the border, and there was great excitement in the castle; but it was soon learned that the invasion was not on a great scale, neither the Douglases nor the Earl of March having taken part in it. "There is no fear of our being attacked, here," Alwyn Forster said to Oswald. "The sheriffs of the county will call out their levies, and will soon make head against them. At the same time, we shall make preparations against any chance of their coming hither." This was done. Vast quantities of arrows were prepared, stones collected and carried up to the points on the wall most exposed to attack; and orders sent out, by the governor of the castle in the Percys' absence, to the people for many miles round, that on the approach of the Scots all were to retire to refuge, the women and children taking to the hills, while the men capable of bearing arms were to hasten to the defence of the castle. For a time, the Scots carried all before them, wasting and devastating the country. Oswald heard that they had captured, without resistance, his father's hold. He rejoiced at the news, for he feared that, not knowing the strength of the invading force, resistance might have been attempted; in which case all in the hold might have been put to the sword. He had no doubt, now, that his father and mother had retired with their followers to the hills, as they had always determined to do, in case of an invasion by a force too strong to resist. Had the Percys been at home, they might have held out, confident that the Scotch would be attacked before they could effect its capture; but as all the northern lords, with their retainers, were away in the south, it would be some time before a force could be collected that could make head against the Scots. A portion of the Scottish army laid siege to the castle of Wark, on the Tweed. This castle had always played a conspicuous part in the border wars. It had been besieged and captured by David of Scotland, in the reign of Stephen; and two or three years later was again besieged, but this time repulsed all attacks. David, after his defeat at the battle of the Standard, resumed the siege. It again repulsed all attacks, but at last was reduced to an extremity by famine, and capitulated.