They are images that could have easily been lost and never seen again, but reels of 16mm holiday film featuring Melbourne around 1940 were picked up at a garage sale in California and digitally remastered into an online video.The first title slate introduces the film with 'Hello "Kangarooland" Melbourne Australia'.From there, many of the shots illustrate the huge changes the city has undergone.Port Melbourne is almost unrecognisable, and while CBD streets are identifiable, they are resolutely low-rise. But many scenes, such as the familiar face of Luna Park, rowers on the Yarra, and the Botanic Gardens, are timeless.Little is known about the mystery American tourist, who travelled across the Pacific Ocean to Australia around 70 years ago, and filmed his journey from Melbourne, to Sydney and Brisbane, then back to San Francisco by ship.Just a few months ago, 17 canisters of his holiday films - which also featured the US, Hawaii, New Zealand and Mexico - were picked up for $20 at a garage sale in San Jose, California, by local history group the California Pioneers of Santa Clara County.Volunteer Rick Helin only got around to editing the Australian portion of the traveller's trip recently, producing three videos of Melbourne, Sydney and Brisbane and publishing them on YouTube."I'm amazed that it's taken off," he said."It was only this week that I decided to clean, edit and brighten them up because they were very dark films originally… we're quite excited by them."And he's utterly baffled as to who filmed them."The home in which [the films] were located... was of a retired police captain and he never had a camera. The descendants didn't even know they were in the garage," he said."I think he was a Californian - fairly wealthy because he took his car everywhere, he showed it sometimes being put on the boat and lifted off the boat".But perhaps Melburnians can help with the detective work."One of the [homes in the Melbourne video] is fairly modest…and I wonder whether he filmed that because that was the home he was staying in and threw that in there as a compliment," Mr Helin said."We're hoping someone will recognise the house and go 'that's my Aunt Mildred's house!', and maybe we can find out why the house was being filmed."While Melbourne's streets were a little quieter and CBD buildings not nearly as high, the video is a reminder of how much the city had already developed by the 1940s.From the fountains near Parliament, to the pathways and benches in the Botanic Gardens, much of Melbourne is exactly as it was several decades ago.At one point in the film, a rowing eight is seen travelling down the Yarra, a scene that could have been shot yesterday.And somehow this traveller and his camera got access to the home of world famous opera singer Dame Nellie Melba, an opportunity that has only recently been made available to the public.The Californian history group has been using a telecine machine to collate all the old American film they can find in the interests of preserving visual histories from the area.Despite being inundated with local films, Mr Helin has taken on the editing of the unknown tourist's far-reaching travels as somewhat of a pet project."I'm working on New Zealand, we've got Mexico he took a trip to, we've got Guatemala in South America.. and there's three reels we haven't even transferred yet!"The almost nine-minute Melbourne video is getting plenty of positive feedback online, aside from a few comments about the editor's choice of backing tracks, which comically bounce from a grandiose Australian national anthem to Dixieland jazz.But, apparently, that joke is on us. After all the videos Mr Helin and his team have produced, it has become a battle as to who can pick the most "god awful song" to accompany the otherwise silent films.