First I stuck my papers in the entrance of a restaurant to keep them dry . But a man came out and told me to move them because someone might trip.
So I got a pasterboard box from the alley, set it on its side by the lamppost and put my papers inside.
问题：
请问set it on its side的意思是？照字面意思“把硬纸箱放在其一面的上方”讲解不通。
set it on its side：
set是“放置”，it 指“盒子”。on its side 指 “放置的方法”，作“方法状语”，不是地址状语。意思是“一侧放置；不是正面朝上”。
So I got a pasterboard box from the alley, set it on its side by the lamppost and put my papers inside.
【翻译】于是我从小巷里找了一个石膏板盒子，把它侧放在灯柱旁边，把我的报纸放进里面。
on its side 这个使用方法，是“方法状语”，不是“地址状语”。我再举几个类似的例句：
He stood on his head to make the baby laugh. 他倒立着使婴儿发笑。
He lay on his back, his hands behind his head. 他仰卧着，双手扣着后脑勺。
He lay on his stomach, making an earnest business of sleeping. 他这会儿趴在床上，看样子好象睡得正熟呢。