Trying to stringify an object to JSON, but not enough memory to fit the whole thing in memory

How do I do this?

I am currently doing this:

				res.writeHead(200,head);
				res.write("{\"Temp\":");
				res.write(JSON.stringify(HISTORY.Temp));­
				res.write(",\r\"RH\":");
				res.write(JSON.stringify(HISTORY.RH));
				res.write(",\"Pressure\":");
				res.write(JSON.stringify(HISTORY.Pressur­e));
				res.write(",\"AirQual\":");
				res.write(JSON.stringify(HISTORY.AirQual­));
				res.write(",\"Clear\":");
				res.write(JSON.stringify(HISTORY.Clear))­;
				res.write(",\"Red\":");
				res.write(JSON.stringify(HISTORY.Red));
				res.write(",\"Green\":");
				res.write(JSON.stringify(HISTORY.Green))­;
				res.write(",\"Blue\":");
				res.write(JSON.stringify(HISTORY.Blue));­
				res.write("}");

It doesn't seem any better than just doing res.write(JSON.stringify(HISTORY));

either way, it runs out of memory halfway through (the main reason being that some of the arrays being stringified are floats, so they get printed with a billion decimal places). I see that there's the .drain callback, but I can't find any example about how to use this. How do I keep track of where in the process I am so I know what to stringify next?

Thanks!