Fit pastry into 9 inch pie pan. Put rhubarb in pastry lined pan. In a bowl beat egg yolks, cream, 2/3 cup sugar, and flour until smooth. Pour mixture over rhubarb. Bake in a 375 oven on lowest rack until pastry is golden brown and custard appears set in the middle when the pie is jiggled, about 40 to 45 minutes. You may meed to cover the edges of the pastry to prevent over browning. In a large bowl, beat egg whites and cream of tartar at high speed with an electric mixer. When frothy gradually whip in the remaining sugar and vanilla, beating until whites hold stiff, glossy peaks (be careful not to over beat). Pile meringue onto hot filling. With a spatula, swirl meringue over filling and up against pastry rim. Bake in a 400 oven until meringue is tinged brown, 3 to 5 minutes. (note if you are woried about saftey you must continue past this until the center of the meringue is 160 degrees, about 7 minutes). Serve warm or at room temperature. If made ahead, let cool, then cover without touching meringue and chill up until the next day. Unfortunately, this pie does not hold well and is best served the day it is made. David Monteith dmonteit@eecs.wsu.edu