He ran back and saw his feet disappear through the window, and had at once sent up for me.

He was only in his night gear, and cannot be far off.
The attendant thought it would be more useful to watch where he should go than to follow him, as he might lose sight of him whilst getting out of the building by the door.

He is a bulky man, and couldn't get through the window.
I am thin, so, with his aid, I got out, but feet foremost, and as we were only a few feet above ground landed unhurt.
The attendant told me the patient had gone to the left, and had taken a straight line, so I ran as quickly as I could.

As I got through the belt of trees I saw a white figure scale the high wall which separates our grounds from those of the deserted house.
I ran back at once, told the watchman to get three or four men immediately and follow me into the grounds of Carfax, in case our friend might be dangerous.

I got a ladder myself, and crossing the wall, dropped down on the other side.