MR. SPARROW states that the widespread use of babbitt as a bearing material may be due to the fact that metal-to-metal contact over a small portion of the surface causes the material to soften and crush without damaging the journal or communicating sufficient heat to the remainder of the bearing to destroy the oil film.
To some extent copper-lead mixtures are superseding babbitt for main and connecting-rod bearings, and Mr. Sparrow discusses these primarily from the standpoint of their performance in comparison with that of babbitt.
Regarding both bearing materials comments are made upon such subjects as cracking, bonding, thickness, life, overheating, disintegration, lubrication and the use of suitable oils, and the results of numerous tests are presented.