//0-2
    this.masses.push(new mass(new cartesian(-30, 15), this));
    this.masses.push(new mass(new cartesian(-15, 15), this));
    this.masses.push(new mass(new cartesian(15, 7), this));
    this.masses.push(new mass(new cartesian(30, 7), this));
//4-9
    this.masses.push(new wheel(new cartesian(-50, 25), this));
    this.masses.push(new wheel(new cartesian(-30, 25), this));
    this.masses.push(new wheel(new cartesian(-10, 25), this));
    this.masses.push(new wheel(new cartesian(10, 25), this));
    this.masses.push(new wheel(new cartesian(30, 25), this));
    this.masses.push(new wheel(new cartesian(50, 25), this));
//springs 1-3
    this.springs.push(new spring(this.masses[0], this.masses[1], this));
    this.springs.push(new spring(this.masses[1], this.masses[2], this));
    this.springs.push(new spring(this.masses[2], this.masses[3], this));
    this.springs.push(new spring(this.masses[3], this.masses[0], this));
//springs 4-9
    this.springs.push(new spring(this.masses[4], this.masses[5], this));
    this.springs.push(new spring(this.masses[5], this.masses[6], this));
    this.springs.push(new spring(this.masses[6], this.masses[7], this));
    this.springs.push(new spring(this.masses[7], this.masses[8], this));
    this.springs.push(new spring(this.masses[8], this.masses[9], this));
    this.springs.push(new spring(this.masses[4], this.masses[9], this));
//springs 12-14
    this.springs.push(new spring(this.masses[0], this.masses[5], this));
    this.springs.push(new spring(this.masses[1], this.masses[6], this));
    this.springs.push(new spring(this.masses[2], this.masses[7], this));
    this.springs.push(new spring(this.masses[3], this.masses[8], this));