88 
OF THE MUSCLES. 
autem ductu, tendinum colore, insertionum proportione, 
et trochlearium distributione, oculis exposita, oilmen su¬ 
perant admirationem.” 
The following remarks upon the structure of the tendons, from the An¬ 
imal Mechanics already quoted, will form an instructive addition to the fore¬ 
going chapter, to the subject of which they bear a near relation.— Ed. 
Of the Cordage of the Tendons. 
Where nature has provided a perfect system of columns ana 
levers, and pullies, we may anticipate that the cords by which the 
force of the muscles is concentrated on the movable bones, must 
be constructed with as curious a provision for their offices. In 
this surmise we shall not be disappointed. 
To understand what is necessary to the strength of a rope or a 
cable, we must leam \yhat has been the object of the improve¬ 
ments and patents in this manufacture. The first process in rope¬ 
making, is hatchelling the hemp: that is, combing out the short 
fibres, and placing the long ones parallel to one another. The 
second is, spinning the hemp into yarns. And here the principle 
must be attended to, which goes through the whole process in 
forming a cable; which is that the fibres of the hemp shall 
bear an equal strain: and the difficulty may be easily conceived, 
since the twisting must derange the parallel position of the fibres. 
Each fibre, as it is twisted, ties the other fibres together, so as to 
form a continued line, and it bears, at the same time, a certain por¬ 
tion of the strain, and so each fibre alternately. The third step of 
the process is making the yarns. Warping the yarns, is stretching 
them to a certain length; and for the same reason, that so much 
attention has been paid to the arrangement of the fibres for the 
yarns, the same care is taken in the management of the yarns for 
the strands. The fourth step of the process is to form the strands 
into ropes. The difficulty of the art has been to make them bear 
alike, especially in great cables, and this has been the object of pa¬ 
tent machinery. The hardening, by twisting, is also an essential 
part of the process of rope-making: for without this, it would be 
little better than extended parallel fibres of hemp. In this twist¬ 
ing, first of the yarns, and then of the strands, those which are on 
the outer surface must be more stretched than those near the cen¬ 
tre ; consequently, when there is a strain upon the rope, the outer 
fibres will break first, and the others in succession. It is to avoid 
this, that each yarn and each strand, as it is twisted or hardened, 
shall be itself revolving, so that when drawn into the cable, the 
whole component parts may, as nearly as possible, resist the strain 
in an equal degree; but the process is not perfect, and this we 
must conclude from observing how different the construction of a 
tendon is from that of a rope. A tendon consists of a strong cord, 
apparently fibrous; but which, by the art of the anatomist, may 
be separated into lesser cords, and these, by maceration, can be 
