Here we have solar power from the 1920s. The title calls it a "Sun Motor" but the text already knows it as a "Solar Motor", though it seems odd that they only use it to boil water. After all if you even only scratch the surface it becomes clear that even before the birth of Jesus Christ, humans already knew how to light fires by using devices very similar to our own magnifying glasses, and their use was also common in Ancient Greece and Rome, where they mystified crowds of onlookers during secular and religious ceremonies by making fire from just a quizzing glass.
This card is the less common export version of the W.D. & H.O. Wills "Famous Inventions", (which you can see at https://csgb.co.uk/cardoftheday/2022-09-01). This was circulated in New Zealand - though as our World Index tells us, export also included Malaya and Malta. The main difference to the front is that on the left of the dish there is no "WILLS` CIGARETTES", the space is blank. The other difference is on the reverse, where our "W.D. & H.O. WILLS" banner meets the sides. rather than have decoration between the side and the framelines - and below that, where we have a scroll rather than the home issue`s I.T.C. Clause, which says "ISSUED BY THE IMPERIAL TOBACCO Co (OF GREAT BRITAIN AND IRELAND) LTD."
Now there is a question for you all, because we are told that this version was not a re-issue, but a reprint. The front subjects were identical, but the text and the titles are often revised and the numbering entirely different. And a quick comparison proves this to be true.
UK / EXPORT numbers - card title - text differences
1 / 27 - Cugnot`s Traction Engine
2 / 49 - Marconi Transmitting Apparatus
3 / 47 - Vacuum Flask
4 / 37 - Arkwright`s Spinning Machine
5 / 46 - Vacuum Brake
6 / 39 - Steam Navvy
7 / 4 - Syphon Barometer
8 / 12 - Rock Drill
9 / 31 - Edison`s First Phonograph
10 / 36 - Spectroscope
49 / 42 - The Sun Motor - text identical
Ok. this is going to be rather a task - so can anyone out there supply more details ? Over to you.... with thanks