Good old Mary Blewitt!!
For many years I have had her little hard cover Blue Book, Fifth Edition, 1971, Celestial Navigation for Yachtsmen (P.C. persons) and her little hard cover Orange Book, Third Edition, 1973, with a Foreward to the First Edition by Captain John Illingworth R.N. (Ret.), Navigation for Yachtsmen (P.C. persons).
I must confess to not having read either book fully due to losing patience with her writing style and having learnt the same things by a different method.
Be that as it may I have recently discovered I own a copy of her tenth edition of her blue book, Celestial Navigation for Yachtsmen (P.C. persons), plus some other very interesting gear (see photos) that may be of interest to one or two of the contributors to this thread.
How I came into ownership and possession of these items was by my purchase of the fair yacht and Australian Registered Ship "Cisco" in mid January 2006, and in one of the drawers of the nav station of the aforesaid yacht, I found the aforementioned items.
At the time of purchase she was called "Onsala" which is the name of the place up a Norwegian Fjiord where the previous owner grew up. I couldn't do anything with THAT name and as I had previously owned a yacht called "Pancho" and there was no "Cisco" on the register, I changed her name during the transfer of ownership.
The thrust of my post is to inform those who may be interested that the items photoghaphed are for sale.
Since the purchase of the yacht in 2006 she has been sitting in the hard stand cradle waiting for me to do something. I am now doing something which is getting the yacht ready for relaunching. As my intended use of the fair "Cisco", being a Van De Stadt 34, is fast and very comfortable coastal cruising in east Australian waters, I have no real use for celestial nav capabilities.
A couple of you might say, "Hang on. I thought this bloke said he had an S&S34!!" You are right. I do. Admirals are at least twice as insane as Captains!!

So the Casio calculator fires up as it has power supply. Google the model number to see what it will do. It is a Casio fx-82LB scientific calculator with manual.
The Sharp is a PC 1248, with manual plus two copies of the Petrel Marine Navigation Manual (software by Roy Rado). Also included is the Sharp CE-124 Cassette Interface. The Sharp has had no batteries in it for at least the last 4 years if ever. It may very well be a VIRGIN. The cassette interface unit certainly is. Apparently the software is loaded into the pocket computer via the interface.
I do not have the software but I am sure a good Googler could find it.
None of the gear has the least sign of salt exposure and there are all the tables on the laminated sheets as well as examples of calculations. Then of course there is Mary's little Blue Book, 10th edition, 1990.
I figure the complete package is worth at least $200. Any advancements on that??
Cheers Cisco.
P.S. The money will go to a good cause. The refirb and relaunch of the fair yacht "Cisco".
Here are the pics:-