var tallestDiv = 0;

function standardiseArticleHeight(selector) {
    selector.each(setTallestDiv);
    selector.each(function(index) { $(this).height(tallestDiv + 5); })
}

function setTallestDiv(index) {
    if ($(this).height() > tallestDiv) {
        tallestDiv = $(this).height();
    }
}