There is an English saying, “A picture is worth a thousand words.” We cannot experience the past directly, but we can learn a lot from pictures. Take a look at Picture 1.
　It shows the Nihonbashi Bridge area of Edo crowded with people around the year 1800. Looking at it, you may feel as if you were actually there in what was called “Great Edo.” Edo became one of the world’s largest cities when its population surpassed one million in the early 18th century. A hundred years earlier, at the beginning of the Edo Period, only 150,000 people lived in the city. What made Edo grow so rapidly in just one century?
　A large number of fires struck Edo. And ironically, this was one of the major causes of the “population explosion.” To explain this, let’s look at Picture 2 — a picture of the “Great Fire of Meireki” of March 1657.
　It was the biggest and worst fire of all. It kept burning for three days and reduced 70 percent of Edo to ashes. Many people burned to death or drowned in rivers they had jumped into in order to escape the flames. Others were crushed to death under collapsing houses and still others froze to death outside. The number of deaths reached somewhere around 60,000.