On 20 February 1890, he and his family emigrated from England, sailing from London on the SS Doric and settling in New Zealand in the Wellington suburb of Newtown.

He entered Victoria College, where he was a chemistry student under Professor Thomas Easterfield; he graduated MSc with first-class honours in 1911.

[1] Rigg had followed his father into the Quakers and so, when war began, he looked for humanitarian work and joined a relief organisation of the Society of Friends.

He distributed food and money to the needy in France, Albania, Montenegro and Russia, and was able to use his organisational and agricultural skills to assist in the farming recovery and the relief of refugees.

In 1920, back in New Zealand, Rigg joined the foundation staff of the Cawthron Institute, Nelson, under the directorship of his former mentor, Easterfield.