74 



ANIMAL MECHANICS. 



tension of the muscle, which resembles the tension of a 

 stretched cord. 



4. He has misunderstood the mechanical conditions of 

 equilibrium of a many -jointed lever, or funicular polygon. 



5. From not being acquainted with the composition of 

 forces, he has misunderstood the action of penniform and ra- 

 diating muscular fibres. 



Errors 1 and 2 may be regarded as errors of observation ; 

 but 3, 4, and 5, are mechanical blunders; — and I have there- 

 fore calculated the following forces from Borelli's experiments, 

 correcting all his erroneous mechanical inferences. These 

 forces may be regarded as Borelli's results, including errors of 

 observation only : — 



Table X. — Borelli's Observation of Force of Muscles, 



1. Biceps humeri and Br •achiceus (Prop, xxii.), . 



2. Biceps humeri (Prop, xxiv.), 



3. Br achiceus (Prop, xxiv.), 



4. Biceps femor is, Gracilis, Semimembranosus, and Scmi- 



tendinosus (Prop, xxvii.), 



5. Vastus externus etinternus, Crurceus, (Prop, xl.), . 



6. SoIcbus (Prop, xli.), .... . 



Solceus (horse) (Prop. xli. scholium), 



Solceus (swan) do. do., . 



7. Glutcei (Prop, liii-), 



8. Solceus (Prop, liii.), 



9. Flexor pollicis longus (Prop, lxxxvi.), 



10. Temporales et masseteres (Prop, lxxxviii.), 



6. On the Comparative Anatomy of the Tendons of the Hand 

 and Foot, and their Mechanical Uses. — The maximum force 

 exerted by muscles has been shown in the preceding section 

 to be proportional to the cross sections of those muscles, and to 

 amount to upwards of 100 lbs. av. per square inch of section. 

 The relative values of the maximum efforts resisted by the ten- 

 dons of the various muscles may be more readily ascertained by 

 comparing together the cross sections of their several tendons 



