310. Proximate cause.

Where loss or damage is the effect or outcome of concurrent causes, the proximate cause is not necessarily that which occurs last in point of time1. The question is one of fact, namely which was the direct or dominant cause of the casualty2. The preceding cause may, in fact, for the purpose of an exception, be the effective cause of the loss3. Thus, where the water gains access to the cargo through a porthole negligently left open