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) (14797458723).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) (14797458723).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) (14777149672).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) (14753993496).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) (14797458723).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) (14777557085).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) (14590839860).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) (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) (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) (14774639244).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) (14773842831).jpg - Wikimedia Commons