Our second clue card was a bit technical but the word we were after was "loop", and that is one of the main distinguishing marks on a fingerprint. It is a simple one too, it just goes up, curves round, and returns.
In fact they look very much like the result of curving wire round the nose end of a pair of pliers, repeated one after the other, growing gradually smaller in width. They are off centred, and usually the loop, or closed end, points towards the thumb of that hand. However, sometimes, this is reversed, and the open end points towards the thumb.
Loops are the most seen of all the marks on a fingerprint, as almost three quarters of the population have them, in varying sizes and slightly different shapes.
This is the third in the group of sets issued by Godfrey Phillips which were intended to encourage people to build their own wireless equipment, starting with a wireless set in 1923, and adding a valve amplifier the following year.
Our original Godfrey Phillips reference book, RB.13, describes this as :
91. 25. How to Build a Two Valve Set. Small cards, size 67 x 35 m/m. Fronts lithographed in brown and white. Backs in brown, with descriptive text. Issued 1929.
As usual, this is very much cut down in our World Tobacco Indexes, to simply "HOW TO BUILD A TWO VALVE SET. Sm. 66 x 35. Brown and black. Nd. (25.)"
Oddly this size is different to that quoted in RB.13.