Unusual chess notation I recently bought a chess book that had unusual chess notation, such as B x KP;  P X B, Q - R5

Does anyone know what type of notation this is and how to read it?
That's descriptive notation. Click that to go to the wiki page.

It is an obsolete notation, having been replaced by algebraic or figurine algebraic notation.

B x KP means, Bishop (B) takes (x) Kings (K) Pawn (P).

Q-R5 - Queen (Q) Moves To (-) Rook's (R) Fifth square (5)

Then there are ways to show castling, etc.

EDIT - doubled pawns.  Descriptive Notation doesn't care how pieces got on the squares where they sit. Just name the piece and where it is going. If you were white and had a pawn on e4 and another on e6 (or K4 and K6, in descriptive) and you moved the pawn on e6, your move would be P-K7.

One thing about descriptive, is that the squares are numbered with respect to the side that is moving.  Say you wanted to move your Queen from her initial square to the opposite edge of the board. Your move, as white, would be Q-Q8 (Queen moves to the Queen's eighth square).  Now suppose you wanted to make the exact same move, but as black. This move would also be Q-Q8. Both moves are notated with respect to the side making the move.