On offer here is this antique French cathode ray tube. To be more precise it is a Crooks Maltese cross tube French circa 1920. There is a wonderful website called the cathode ray tube site which gave me this information which can also tell you all about this piece. On this website this can be found on the second page of the Crooks tube section. I have been lucky recently to make a new contact in the Czech Republic who clears schools and colleges both in Czechoslovakia and east Germany and he has found me some fantastic things recently this wonderful example was with them.
It consists of a large zeppelin shape glass tube with nickel electric attachments at the thin end and on the stem of the glass. Inside is a Maltese cross which stands up and is hinged to also lay flat.
The experiment is to introduce an electrical current which charges the particles inside the vacuum to project a image of the maltese cross on the front large section of the glass then when the cross is removed this section of the glass will change colour at a different rate leaving the picture of the cross on the glass. This is of course the forerunner to the cathode rays tubes used in old televisions.
All of this can be explained on the website mentioned above. These old TUBES are collectable and can command high prices by collectors, I've picked this up quite a reasonable price so I'm not being greedy.... It is in good condition, there is a little bit of oxidisation on the inside of the tube this can be seen clearly from the pictures. But there are no cracks or chips to the glass it is all in very good condition. This has been taken into consideration when pricing.The grass does come out of the stand, the stand is turned and polished Beechwood. The item "ANTIQUE CATHODE RAY TUBE SCIENTIFIC INSTRUMENT FRENCH 1920 CROOKS MALTESE CROSS" is in sale since Tuesday, March 24, 2020. This item is in the category "Collectables\Scientific Collectables\Optical". The seller is "barrie5757" and is located in cambridge. This item can be shipped worldwide.