  A key problem is that laws established at the level of observation and experiment involve or imply properties other than the primary ones of the mechanical atomist. As mentioned above, the mechanisms of clocks involve the elasticity of springs, the weight of pendulum bobs and the rigidity of gear wheels and the law of fall presupposes a tendency for heavy objects to fall ‘downwards’. So the mechanical atomist cannot apply knowledge of this kind, scale invariant or otherwise, to atoms that are presumed to lack such properties. If we are looking for an empirical case for the list of properties that can be applied to atoms then it would appear that we need some criteria for picking out that subset of properties possessed by observable objects that can be applied to atoms also. Boyle offered a solution to this problem. He suggested that only those properties that occur in all observable objects whatsoever should be transferred to atoms. Since all observable objects have some definitive shape and size then atoms do also. By contrast, whilst some observable objects are magnetic, many are not, and so atoms are not magnetic. This strategy does not give an atomist what is needed. All observable objects are elastic to some degree and are even divisible to some degree and yet mechanical atoms are denied such properties. Conversely, no observable macroscopic object is absolutely impenetrable whereas Boyle assumes that atoms posses precisely that property. Perhaps it should not be surprising that the mechanical atomists of the seventeenth century lacked the resources to forge links between their conjectured atoms and experimental findings.