If the engine quits over inhospitable terrain, I'll figure about
500 ft lost per mile. I'll also be aiming for a field within about
7:1 glide to a point 1000 feet above the field.
I'll be using visual cues primarily.  With my thumb against the
bridge of  my nose, I put the top of my index finger on the horizon.
If I can see something under the finger, I can fly to it with a 7:1 glide.

For 15:1, I use the tip of my thumb against my forehead and
put my pinky fingernail on the horizon. The pad of the pinky is
little better than 15:1.

Bob,

 

Can you send your head and hand dimensions so that I can construct an inclinometer?

 

Dang, you have flown more years without engines than I have flown with 1 or more tugging the airframe along.

 

I carry a cheap split mirror level and sighting device (from the local Home Depot) to determine if clouds ahead are above or below my altitude.  Maybe I could Rube Goldberg something like that for a descent angle.  I love gadgets. 

 

Oh, OK, I guess I'll just have to stick a finger up my nose and one in my ear, placing a knuckle on the horizon and looking thru the vee formed by the index finger and an adjacent one to find a landing spot within gliding range. ;<)

 

BTW Paul and Bob, I learned way more than you guys did from this exchange.