Two questions. Now that the tower has been basically approved and shelved, can I dream and ask what would stop the owners from proposing to add 300 feet (roughly) to the Westin while also reclading it and combining that with project? The resulting building, (One Copley) could be absolutely stunning. The real question though, and this is the reason I posted is this; what the heck is that low droning horn noise that pervades that intersection of Dartmouth and Stuart St.? I have lived in the neighborhood for more than a decade and not only do I not know WHAT it is, but for the life of me, I cannot figure out even WHERE it is coming from. Short of talking to an engineer from the MBTA I figure this is the place to ask.