The small books were full of information: mathematics, railroads, astronomy .... "At that time we really felt these things were incredible!"
小小薄薄的一本，談的東西可不少，計有算術、養蠶、鐵路、飛機、天文、化學…… 等，「雖然只有文字描述，但我們那時候看到講天文、航空這些內容，覺得真不可思議！」