the solution was to modify the css property which fixes the size of the content displayed in UIWebView
, then reduce it by half
NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'padding: 0px; height: %fpx; -webkit-column-gap: 0px; -webkit-column-width: %fpx;')", webView.frame.size.height, webView.frame.size.width/2];