Snippet to auto-scroll a page but 1 line every 3s. Used for reading on Project Gutenberg.
javascript:(function() {
var scrollEvery = 3 // seconds
var scrollByPx = 16 // 16px one row or so
var a;
function autoscroll() {
a = window.setTimeout(scrollOneRow, scrollEvery * 1000);
}
function scrollOneRow() {
window.scrollBy(0, scrollByPx);
autoscroll();
}
function stopAutoscroll() {
clearTimeout(a);
}
autoscroll()
})();