paragraph: The day was just breaking, as I left the tower; though it was still too dark in the house to be able to see without a light, and I took one of the study candles with me on my 'round.  By the time I had finished the ground floor, the daylight was creeping in, wanly, through the barred windows.  My search had shown me nothing fresh.  Everything appeared to be in order, and I was on the point of extinguishing my candle, when the thought suggested itself to me to have another glance 'round the cellars.  I had not, if I remember rightly, been into them since my hasty search on the evening of the attack.  For, perhaps, the half of a minute, I hesitated.  I would have been very willing to forego the task--as, indeed, I am inclined to think any man well might--for of all the great, awe-inspiring rooms in this house, the cellars are the hugest and weirdest.  Great, gloomy caverns of places, unlit by any ray of daylight.  Yet, I would not shirk the work.  I felt that to do so would smack of sheer cowardice.  Besides, as I reassured myself, the cellars were really the most unlikely places in which to come across anything dangerous; considering that they can be entered, only through a heavy oaken door, the key of which, I carry always on my person. 
question: How many floors are there?
answer: Three