Lengthways not perpendicular

Q: The problem I have is the room that I want to lay the hardwood down is long- about 40 feet and about 15 feet wide. The floor joist run parallel to the length of the room and I would like to lay the hardwood lengthwise not perpendicular to the joist. I keep hearing that its better to lay the floor perpendicular across the floor joist to provide stability.

Any suggestions for me so I can run the floor length wise on the room? Is it necessary to lay them perpendicular to the joist or can I get away and run them parallel to the floor joist?I have a 3/4 plywood subfloor.

A: You would need to install another layer of 3/4 plywood first, then you will have the stability to run parallel to the joists.