How does varying the amount of magnetite material affect the device?
A. No one knows for sure, but it appears to me that it is important that the bottle or water (or other liquid) be completely surrounded by a cylinder of magnetite sand or powder for at least 85% to 90% of its height (that is, the height of the water or liquid in the bottle) and that the cylinder of magnetite sand/mixture be at least 0.8 inches (at a minimum) to 1.5 inches thick (i.e., forming a shell of magnetite powder at least 1.5″ thick in all directions around the radius of the bottle.) While I do own and use a number of the cardboard oatmeal can versions of the MEOW kettles which empIoy a cylinder of magnetite with a radial thickness of only 0.92 inches (in other words, just under one inch), I personally prefer a larger mass of magnetite and a larger radial thickness of magnetite sand, more on the order of 1.2 inches or greater. Some of my plastic designs for the MEOW kettles, in addition to offering a far more robust and sturdy construction, offer a cylindrical shell of magnetite
