to laurence also ; the letters were slant and wavering , but this kind of affliction , he did not say to staunton , was not uncommon ; aviators were taken into service at the age of seven , and the most promising among them often became runners by ten , with studies neglected sadly in favor of practical training : his own young cadets were inclined to grumble at his insistence that they should learn to write a graceful hand and practice their trigonometry .