I see this paragraph in "The life of Samuel Johnson"

I see this paragraph in "The life of Samuel Johnson"

"Pope, who then filled the poetical throne without a rival, it may reasonably be presumed, must have been particularly struck by the sudden appearance of such a poet; and, to his credit, let it be remembered, that his feelings and conduct on the occasion were candid and liberal. He requested Mr. Richardson, son of the painter, to endeavour to find out who this new authour was. Mr. Richardson, after some inquiry, having informed him that he had discovered only that his name was Johnson, and that he was some obscure man, Pope said; 'he will soon be deterre.' We shall presently see, from a note written by Pope, that he was himself afterwards more successful in his inquiries than his friend."

What mean of "deterre"? I think it is french word

And What mean of "We shall presently see, from a note written by Pope, that he was himself afterwards more successful in his inquiries than his friend".

I think it means Pope understand Johnson better than Richardson. Right or wrong?

From the context, the translation of the French verb déterrer (to unearth) fits pretty well. As in 'he (and his identity) will soon be déterré (unearthed or uncovered). Presumably, the inference is that very talented people are rarely unknown or obscure, as their talents are already known in certain circles, even if not widely publicised.

'We shall presently see' is a narrative device to inform the reader that all will be revealed - if you are patient enough to read on!