Mottingham 4 August 1585: The cause of the incident, referred to as a "marvellous accident" at the time, was then unknown, and it is likely that a sinkhole had developed. The area is well coursed with streams, both above and below ground, and the collapse or shifting of subsoil might be attributed to them. The site of the sinkhole is now unknown, and the incident is also largely unknown. The only body of standing water that is in the area today is a lake at The Tarn Bird Sanctuary. In the NW corner of The Tarn opposite Mottingham Station is an
Void (composites) void content of approximately 1% is appropriate for performance while other grades of composites can have between 3%-5% void content. A small change in the percentage of void content may not seem like a large problem however for a loaded carbon fiber laminate composite, a 1%-3% increase in void content can reduce the mechanical properties of the composite by up to 20% Void content in composites is represented as a ratio, also called void ratio, where the volume of voids, solid material, and bulk volume are taken into account. Void ratio can be calculated by the formula below where e