1ADV [oft ADV before v]从那里;由此Thence means from a particular place, especially when you are giving directions about how to get somewhere. 从那里;由此 [formal, old-fashioned]
I ran straight up to Columbia County, then turned East, came down the Harlem Valley and thence home.
我一直跑到哥伦比亚县,然后向东转,沿着哈勒姆山谷,从那里回到家。
The mosaics were sent to Munich, and thence to Geneva.
那些马赛克被送到慕尼黑,从那里又送到日内瓦。
2ADV [oft ADV before v]然后,接着(指状态的变化)Thence is used to say that something changes from one state or condition to another. 然后,接着(指状态的变化) [formal, old-fashioned]
...the conversion of sunlight into heat and thence into electricity.