Hugh Farmer's dream is to trace the history of the incense industry in old Hong Kong "because that's how [the city] was named".
The former English teacher turned historical researcher was referring to the "heung" in Heung Gong, the Chinese name meaning fragrant harbour that colonists adapted as Hong Kong.
The incense study is part of the research he is conducting through the Industrial History of Hong Kong group he established in November 2012. The group receives donations, sends newsletters to subscribers and runs the website industrialhistoryhk.org
"I felt it was an immensely important part of Hong Kong history which involved huge numbers of people here and which was being rapidly forgotten."
Farmer has learned much about the city's past, including its textile spinning industry, launched in the late 19th century.
The first cotton spinning factory was opened by Jardine Matheson in So Kon Po, but moved to Shanghai in 1914 because of a lack of skilled workers, electricity and clean water. High humidity also made the city unsuitable for spinning yarn.
When South China Textile opened after the war it was found that the heat generated by the machines dispelled the high humidity and the industry expanded rapidly in the following two decades. By 1975, there were 40 spinning mills in Hong Kong, employing 350,000 workers - half the total workforce at that time.
All that remains of the industry is a lump of concrete in Mok Cheong Street, To Kwa Wan, part of the façade of Eastern Cotton Mills that was established in 1954 and closed in 1981.
Ginger factories provided a fragrance of a different kind. One of the first was Man Loong, which opened in the late 1860s in Temple Street.
Ginger was transported to the city from Guangdong, where it was peeled and boiled. It was preserved using syrup and cane sugar in Hong Kong, and exported to Chinese communities in the US, Europe and Australia.
Farmer hopes his group will soon host meetings, lectures and field trips, so the city's industrial heritage will not be forgotten.
"Perhaps one day there will be an industrial history museum in Hong Kong," he said.