Peak torque arrives quickly, at 3, 250 rpm, and the squirt from a standing stop to that rpm comes on with great urgency because the newest Bentley uses twin turbochargers that spool up very rapidly.

FORBES: Bentley Arnage T

The engine note is pleasing, too, with just a touch of turbo spool-up from under the hood and a nicely resonant thrum coming from the dual exhausts.

WSJ: 2013 Ford Escape Titanium With AWD Review: Kick Up Your Suburban Heels | Rumble Seat by Dan Neil

The good news: no spool-up lag.

FORBES: Magazine Article

Unfortunately, the Leica's take-up spool needs a long tapering tongue of film, which users must wedge under a spring clip on the spool's barrel before manually wrapping a few turns of film around it.

ECONOMIST: A die-hard analog photographer goes digital

In their bid to simplify loading 35mm film, Kodak, Fuji and other photographic firms squared off the 35mm roll's lead-in tab so a modern SLR's motor-driven loading mechanism could grab the film's sprocket holes and wind it automatically onto the take-up spool.

ECONOMIST: A die-hard analog photographer goes digital

Another issue is finding the right tubing that is flexible enough to wind up on a spool but resilient enough to not bend or break, either from internal fluid pressure or by being cut by plants and rocks on the landscape.

FORBES: Startup Aims To Install Pipelines With Helicopters...Seriously!

Using Spool, Twine can be set up to send emails, tweets or text messages depending on the inputs from its sensors.

FORBES: Interview: Twine - The Internet of Things for Regular People?

The share price decline came on the same day Facebook announced it had purchased the management of Spool, a San Francisco based start-up that produces smartphone and tablet apps that allow consumers to bookmark web articles and video on their devices.

FORBES: Investors Shrug Off Ralph Lauren's Olympic Controversy