I'm at a slight disadvantage because my Spinning files are all at work and it's the weekend - but I think that you are probably mistaken.
My understanding is that the spin recovery was first cracked around 1915-1916 by a chap called (Alan?) Parke, leading to it being known as Parkes dive for a while. I've never come across any reference (including in Tommy Sopwith's biography which I read recently) to Hawker doing much work in that direction.
Also if we're talking about 1914 and thus pre-WW1 aircraft they had very little tendency to spin. Their problem was excessive directional stability tending to cause them to lock into a nonrecoverable spiral dive.
It may be that what you are investigating (I honestly don't know) is Harry Hawker doing work on the excessive directional stability / spiral dive issues of the time, leading to less directionally stable aircraft which were thus much safer in normal use but would spin.
If you wish give me a day or two, and I'll post a list of references on the spin mode - albeit not so much from a historical perspective it is one of my research interests. In the meantime, you might find some useful stuff on the NACA reports server.
G