That is the correct scansion for that line - the poem is written in dactylic hexameter - and the stressed and unstressed syllables don't alternate. The patterns of stressed and unstressed syllables alternate, but in this case, the pattern is X / /, not X / or / X. The best guideline is to say the line normally and be patient.
An isobar refers to all of the nuclides of all elements that have a particular atomic mass. For example, helium-6 is one of the many isotopes of helium. The isobars of helium-6 are hydrogen-6, lithium-6, beryllium-6, and boron-6.
(Ä«'sÉ-bÃ¤r') A line drawn on a weather map connecting places having the same atmospheric pressure. The distance between isobars indicates the barometric gradient (the degree of change in atmospheric pressure) across the region shown on the map. When the lines are close together, a strong pressure gradient is indicated, creating conditions for strong winds.