javascript object works on a html page but can not be loaded in wordpress

this piece of code works fine on a html page. (put in the header)

var startstop = new (function() {

    console.log('startstop called');

    var $stopwatch, // Stopwatch element on the page
        incrementTime = 70, // Timer speed in milliseconds
        currentTime = 0, // Current time in hundredths of a second
        updateTimer = function() {

            $stopwatch.val(formatTime(currentTime));
            currentTime += incrementTime / 10;
        },
        init = function() {

            $stopwatch = $('.stopwatch');
            startstop.Timer = $.timer(updateTimer, incrementTime, true);
            startstop.Timer.stop();
        };
        this.resetStopwatch = function() {
            currentTime = 0;
            this.Timer.stop().once();
        };
   $(init);
});

When I try to access it on a WordPress page where this javascript is loaded in the header using a theme function console shows $(init) not a function.

What is wrong with this way of object declaration in WordPress?