Southern Lights recounts the story of how New Zealand lighthouses were established through the transfer of technology from Scotland to New Zealand over a period of almost 90 years. This resulted in most of New Zealand's lighthouses being fully or partially built using Scottish materials and expertise. The major Scottish contribution was the professional services provided by the firm founded by Robert Stevenson. The firm of David and Thomas Stevenson took on the first commissions and its successor companies over a period of 80 years were Consulting Lighthouse Engineers to the New Zealand Government. They arranged tenders, advised on technology, supervised manufacture and dispatch of lighthouse components and stores, and much more, proving invaluable to the New Zealand Agent-General in London. It was on this basis that in the period 1859 to 1941, 38 major lighthouses were built; 30 of which were constructed between 19865 and 1897. Thirty-three were built using Scottish-designed and built lanterns and apparatus and Scottish-designed lenses, although these were of French or English manufacture. Of the other five, two were eventually replaced by Scottish lighthouses, two were upgraded with Scottish technology and the fifth remains the sole example of English lighthouse design, although in its time was supplied with Scottish equipment. Scotland also supplied trained professionals who manned the lights, designed and administered them.