Time for clue number two, and that was what bees do, when they fly, which is hum. And humming is another simple noise for anyone to produce, using, once again, just their mouth. Actually the bee does not make the humming noise with their mouth, but with their wings, which vibrate fast enough to disrupt the air and create sound waves.
This set is first recorded in our original Churchman reference book (RB.10), published in 1948, and listed as
103. October 1930. 25 NATURE`S ARCHITECTS. (titled series) Size 2 11/10" x 1 7/16" or 67 x 38 m/m. Numbered 1-25. Fronts printed by letterpress, 4-colour half tone process. Backs in dark green, with descriptions. Printed by Mardon, Son & Hall.
Now if you are not careful, you will close the book and wallk away, but wait. Because directly below it, there is this :
104. May 1930. 12 NATURE`S ARCHITECTS. Similar format to (103) but size 3 5/16" x 2 9/10" or 80 x 62 m/m
Now my first thought was to wonder which twelve were selected, but this was not the case, and if you look back at the dates you will see that the set of twelve large cards were issued first, five months earlier.
Our World Tobacco Issues Indexes list the sets, but without listing the months, as simply :
NATURE`S ARCHITECTS. Nd.
(A) small (25)
(B) large (12)