50 YEARS AGO

“Atomic time and the definition of the second” — The following tentative proposals are put forward in an attempt...to make the atomic standard immediately available but to preserve a single unit of time closely linked with, although not defined by, that given by astronomical observations.

(1) The provisional unit of time should be the time of 9 192 631 830 cycles of the caesium Fm,(4,0)→(3,0) resonance at zero field, and named 1 provisional second...

In making these proposals, the understandable reluctance to break with a practice as old as civilization is fully appreciated; but a consideration of the precision of measurement alone shows that the astronomical unit of time is no longer sufficiently accurate for modern measurements of frequency and time interval.

From Nature 7 July 1956.

100 YEARS AGO

“The olfactory sense in Apteryx” — About a year ago I stated in your columns that I was trying to have some experiments carried out with the object of ascertaining whether the olfactory sense of the kiwi [and roa] is perceptibly developed, as one would suppose it to be from...the great relative size of the olfactory lobes of the brain and the great size of the olfactory capsule as seen in the skull.

I wrote to the curators of Little Barrier and Resolution Islands asking each of them to try certain experiments for me... Mr. Henry placed a number of earthworms at the bottom of shallow buckets and covered them with four inches of earth. When such a bucket was placed on the ground the roa got quite excited in its hunt through the earth, probing to the bottom for the worms. It must be borne in mind that the roa (and kiwi) is practically blind during the day...while Mr. Henry states that it makes such a “sniffling noise” that it would be unable to hear a worm... “when I put down a bucket of earth without worms in it, the bird would not even try it”.

From Nature 5 July 1906.