He seemed to take in everything at a single glance and in an instant to appreciate the meaning of everything that he had seen.
Here was a case in point.

I had myself seen all that he had seen, and, indeed, much more; for I had looked on the very people and witnessed their actions, whereas he had never set eyes on any of them.

I had examined the little handful of rubbish that he had gathered up so carefully, and would have flung it back under the grate without a qualm.
Not a glimmer of light had I perceived in the cloud of mystery, nor even a hint of the direction in which to seek enlightenment.

And yet Thorndyke had, in some incomprehensible manner, contrived to piece together facts that I had probably not even observed, and that so completely that he had already, in these few days, narrowed down the field of inquiry to quite a small area.
From these reflections I returned to the objects on the table.

The spectacles, as things of which I had some expert knowledge, were not so profound a mystery to me.