“So,perhaps,shall break upon us that eternal morning,when cr

“So,perhaps,shall break upon us that eternal morning,when crag and chasm shall be no more,neither hill and valley,nor great unvintaged ocean; ”
希望能分析一下句子语法结构
此句子出自一下文章最后一段开头；
lemonT(2360836737) 09:48:09 An October Sunrise
I was up the next morning before the October sunrise,and away through the wild and the woodland.The rising of the sun was noble in the cold and warmth of it; peeping down the spread of light,he raised his shoulder heavily over the edge of gray mountain and wavering length of upland.Beneath his gaze the dew-fogs dipped and crept to the hollow places,then stole away in line and column,holding skirts and clinging subtly at he sheltering corners where rock hung over grass-land,while the brave lines of the hills came forth,one beyond other gliding.
The woods arose in folds,like drapery of awakened mountains,stately with a depth of awe,and memory of the tempests.Autumn’s mellow hand was upon them,as they owned already,touched with gold and red and olive,and their joy towards the sun was less to a bridegroom than a father.Yet before the floating impress of the woods could clear itself,suddenly the gladsome light leaped over hill and valley,casting amber,blue,and purple,and a tint of rich red rose,according to the scene they lit on,and the curtain flung around; yet all alike dispelling fear and the cloven hoof of darkness,all on the wings of hope advancing,and proclaiming,“God is here!” Then life and joy sprang reassured from every crouching hollow; every flower and bud and bird had a fluttering sense of them,and all the flashing of God’s gaze merged into soft beneficence.
So,perhaps,shall break upon us that eternal morning,when crag and chasm shall be no more,neither hill and valley,nor great unvintaged ocean; when glory shall not scare happiness,neither happiness envy glory; but all things shall arise,and shine in the light of the Father’s countenance,because itself is risen.
By Richard D.Blackmore

我认为 shall break upon us是谓语 that eternal morning是主语,
后面是非限制性定语从句 修饰 that eternal morning
when crag and chasm shall be no more,neither hill and valley,nor great unvintaged ocean.
再问： 谢谢你的回答，好像是这样的。 我之所以疑惑可能就是因为没找到主语 that eternal morning 这种主语放到谓语后面在语法上叫什么句子呀？
再答： 只能是因为 主语 加修饰成分 太长了 所以 放在了后面