File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14590292409).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14777239422).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14590816350).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14777538475).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14776646922).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14777534455).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14591092077).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14590503747).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14754525686).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14775154134).jpg - Wikimedia Commons

File:Machine drawing; a practical guide to the standard methods of graphical representation of machines, including complete detail drawings of a duplex pump and of a direct-current generator (1914) (14590826590).jpg - Wikimedia Commons