The values pertaining to horizontal alignment (which cause "floating spacers") are as follows:
If two spacers, one with align=left and the other with align=right, are close to each other, the wraparound text will proceed through the channel that exists between them. If there is not room in the current window/frame width to allow the two spacers to exists side by side, the second one will move down until sufficient room is available.
Here is a line of text.This markup (unsupported by Internet Explorer):
Here is another line of text, 30 pixels below.
Here is some text with aThe following markup (again unsupported by Internet Explorer) allows you to make space on one side of an image but not on the other (hspace, often used for the purpose of preventing text from butting up against an image, puts space on both sides and thus causes the margin for the image to be different from the margin for the text):
30-pixel space in it.
Here is a photo of Earth taken by Apollo 11 astronauts. This view of Earth was photographed from during Apollo 11's translunar journey toward the Moon. The spacecraft was already about 10,000 nautical miles from Earth when this picture was taken. Portions of the landmass of North America and Central America can be seen.