From Chapter 4:
But to turn from this worthy Exeter citizen to more famous names: I do not know of any good evidence as to whether or not Cromwell smoked, although he is said to have taken an occasional pipe while considering the offer of the crown, but John Milton certainly did. The account of how the blind poet passed his days, after his retirement from public office, was first told by his contemporary Richardson, and has since been repeated by all his biographers. His placid day ended early. The poet took his frugal supper at eight o'clock, and at nine, having smoked a pipe and drunk a glass of water, he went to bed. Apparently this modest allowance of a daily evening pipe was the extent of Milton's indulgence in tobacco. He knew nothing of what most smokers regard as the best pipe of the day—the after-breakfast pipe.

From Chapter 5:
When plague was abroad even children were compelled to smoke. At the time of the dreadful visitation of 1665 all the boys at Eton were obliged to smoke in school every morning. One of these juvenile smokers, a certain Tom Rogers, years afterwards declared to Hearne, the Oxford antiquary, that he never was whipped so much in his life as he was one morning for not smoking. Times have changed at Eton since this anti-tobacconist martyr received his whipping. It is sometimes stated that at this time smoking was generally practised in schools, and that at a stated hour each morning lessons were laid aside, and masters and scholars alike produced their pipes and proceeded to smoke tobacco. But I know of no authority for this wider statement; it seems to have grown out of Hearne's record of the practice at Eton.