In 1891, approximately ten years after Pockels first surface tension measurements, through her brother Friedrich Pockels, she became aware that John William Strutt, 3rd Baron Rayleigh [Lord Rayleigh] was publishing studies of the effect of small amounts of oils on the surface of water. It was clear to her that Lord Rayleighs research was closely related to her own. At the encouragement of her brother, Agnes Pockels wrote to Lord Rayleigh to describe her apparatus, her findings, and the fact that she was unable to publish her findings in the scientific journals of the time. Pockels original correspondence with Rayleigh was in the German language and was translated for Rayleigh by his wife. In an act of generosity and unthreatened by correspondence from an unknown amateur, Rayleigh forwarded Pockels findings to the journal Nature with a suitable cover letter to enable Pockels' findings to be published. Her first paper was "Surface Tension," describing her measurements and findings with her sliding trough.
The letter to Lord Rayleigh was described in a 1971 journal article on the origin of the surface film balance as being "a landmark in the history of surface chemistry." Lord Rayleigh retained his correspondence, and Pockels’s letter to him dated 10 January 1891 began:
The body of Pockels's letter to Rayleigh then described her sliding trough method, her initial findings, and her assessment of the limitations of her experimental methods. The closing of her letter stated:
Lord Rayleigh forwarded Pockelss correspondence to the editor of the journal Nature', with a covering letter dated 2 March 1891. The editor at the time was Sir Joseph Norman Lockyer who chose to publish the correspondence from Rayleigh and Pockels. The covering letter stated:
Ostwald's biography of Pockels reports that Pockels had initially approached physicists at the University of Göttingen about her findings and received no expression of interest.