Here is an example of how you can achieve this:
let scrollDistance = 600;
$("body").click(function() {
$("html:not(:animated), body:not(:animated)").animate(
{scrollLeft: "+="+scrollDistance}, 400
);
});
You can view the code in action on jsfiddle here: http://jsfiddle.net/juXLu/2/
[edit]
Additionally, here is an example of detecting if you've reached the end of the document: http://jsfiddle.net/lukemartin/juXLu/5/
let scrollDistance = 600,
docWidth = $(document).width(),
scrollPosition;
// click event handler
$("body").click(function() {
// animate scrolling
$("html:not(:animated), body:not(:animated)").animate(
{scrollLeft: "+=" + scrollDistance},
400,
function(){
// check current scroll position
scrollPosition = $(window).width() + $(window).scrollLeft();
// determine if at end of document
if(docWidth === scrollPosition) {
$("body").text("End of content");
}
}
);
});