(CNN)It hangs like a low cloud, clusters of porcelain-white spheres forming shadows as if burdened with expectant rain. Gentle white light pulsates through its layers, breathing rhythmically over the ambling shoppers below.
Whether it's a cloud, a slew of bubble bath or a living mass of cells, Charles Pétillon's installation "Heartbeat" is making the tourists of London's Covent Garden Market stop and stare. 100,000 balloons are suspended in the Grade II-listed 19th century building -- a watchful lid over the bustle of buskers, diners and day trippers beneath. In contrast to his previous balloon photography, this creation is warm, comforting. Street performers draw in the crowds, their raised camera phones testament to this shared experience. We spoke to the French artist, formerly a commercial photographer, about his most ambitious project to date.
Previously the public has only seen your work in photographs. What's pushed you to exhibit in a physical space for the first time?
When I show my photographs, a lot of people say, "Is it Photoshop, or CGI?" So when Covent Garden Market asked me to create something here I saw a really interesting opportunity to share it with the public. The balloons are alive - they're really there! I was really excited but a bit afraid, because it's a great responsibility (to fill this space). I didn't want to create something just decorative, it needed to be meaningful.
A staged photo is very different to a free-flowing public installation. Was that change troubling or exciting for you?
I can't control everything in my still life...but in this case it's really exciting. That's the purpose of this installation, to share this immersive experience with people. I'd like to refresh people's view of this space. People are enjoying it and that's great to see.
What were the challenges?
This space is huge. There were 300 kg of balloons - 1000 cubic meters. We needed 20 people to inflate them over five days, and four nights to hang them. There are many underneath that you can't see. You only have to look at my fingers, they are destroyed!
It's called "Heartbeat". Why did you choose this idea?
It's a metaphor -- I wanted to represent the Market Building as the beating heart of this area. When I came here for the first time, I discovered how important it was -- it changed the landscape of the district. When they built Covent Garden Piazza around 1552 (the Market Building later in 1830), all the houses were very new and comfortable, everybody wanted to live here. It changed the way of life for many people. All the life around here was thanks to this market -- it's an icon.
Nowadays I think people who come here forget that. I wanted to create a kind of bridge with the past of this space, to show that it is still alive. Creating a huge heart was the best way to show that.