Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 39 By What Method the Bones and Cartilages of the Human Body May Be Prepared for Inspection

Appendix: Vesalius’ Bow Drill To Perforate Bones for Articulation

Now whenever there are harder or dryer bones than can be freely drilled as people do who pierce a hide with an awl, it will be fitting to apply to the job an instrument which I have sometimes prepared for this purpose when I have encountered extremely hard bones that are most agreeable to view because of the dry temperament of a man of middle age.

In this figure we have illustrated an instrument with which hard bones can easily be pierced. A and B identify two posts which can be inserted into a table or workbench at an angle; C,C are the shaft, D the part of the shaft in which the iron is inserted like a pin. E is the bow with which the shaft is rotated.


I took two posts about three palms in length and about three fingers thick, which were then pierced with a round opening not far from one end big enough to admit a thumb so that a shaft about three palms long and a thumb’s thickness at its ends but of double thickness in the middle would turn in them; this shaft was smoothly rounded so that the ends would fit the holes in the posts and would turn in them easily and the middle thickness would hold the shaft so that when the posts were forced into the angle of a table or workbench along the longitude of this thickness and tightened with the shaft fitted into them, the shaft would be able to rotate only within the posts, and would not be moved forward or backward. In this way, one end of the shaft was smoothly rounded like a thumb for a length of about three fingers’ breadth; but for four or five fingers’ breadth, twice as thick. The rest of the shaft was a thumb’s diameter so as to project beyond the other post and for a distance beyond the width of the table or workbench; into it an iron bit would be inserted with which I would pierce the bones, sometimes taking a thicker bit, sometimes a thinner one according to the task, following the method used by the men who daily prepare beads suited for pious counting in Lord’s Prayers and salutations to the holy Virgin. 55 The middle diameter of the shaft, situated between the braced posts, was perfectly smooth so that a slender thong would more easily turn around it; this was wrapped once around the shaft and tied to the ends of a long rod as on a bow, so that when the rod was moved up and down as in playing the lyre 56 the shaft with the iron bit placed in it would rotate in the posts and perforate the bone which I would hold in my right hand. Pierce the bones with the aid of this instrument or of awls alone; have brass wire ready, some thicker, some thinner; it should afterward be put in the fire until it glows for awhile to make it more flexible and less often broken no matter how much it is twisted.



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 39 By What Method the Bones and Cartilages of the Human Body May Be Prepared for Inspection