No discovery.

Then I pulled out a carpenter's rule which I had brought with me.

Was there anything in the room which--either in inches, feet, or yards--answered to "5 along" and "4 across"?
Nothing.

I put the rule back in my pocket--measurement was no good, evidently.

Was there anything in the room that would count up to 5 one way and 4 another, seeing that nothing would measure up to it?
I had got obstinately persuaded by this time that the letter must be in the room--principally because of the trouble I had had in looking after it.