( 5 ) 



to fix it, in order that there may be no movement while the measure- 

 ments are going on, and in order that the position may, if necessary, 

 be reproduced for the purpose of repeating and testing measurements 

 already taken. For this purpose I have had a small clamp, with 

 a horizontal bar attached to it, made by the Mathematical Instrument 

 Department. The clamp runs on the height measure which is in 

 the box, and is used in the following manner. 



Adjust the subject's head correctly by the plane of vision 

 as explained above. Then place the height measure with its 

 plummet attached on the left side of the subject, and see by 

 observing the plummet that the measure is upright. Run the 

 clamp up until the horizontal bar attached to it touches the central 

 cartilage of the subject's nose, and renders it impossible for him to 

 depress his head. Then screw the clamp tight. The bar will rest 

 exactly at the junction of the upper lip with the central cartilage — at 

 the point, in fact, which forms the lower starting point for the 

 measurement of the height of the nose (0 — O 1 in Fig. 1). So 

 long as the subject rests his nose on this bar he will be in the 

 correct position as previously ascertained ; and if the height of 

 the bar on the graduations of the height measure is noted, the 

 position can be reproduced at any moment. In fact the sources of 

 error are reduced to one — the possibility of the subject raising his 

 head — and this can be easily guarded against by seeing that his 

 nose is tightly pressed against the horizontal bar. 



It will be seen the horizontal bar in no way interferes with 

 the process of measuring. It may even assist it, if the vertical 

 arm of the T — square be steadied against the horizontal bar in 

 taking the dimensions from vertex to tragus. 



The position of the head being thus secured, a few remarks 

 may be added on the details of the measurements. 



Height from vertex to intersuperciliary point (H — I in Fig. 1). — 

 The intersuperciliary point is defined by Topinard as " situated 

 in the centre of a line drawn at a tangent to the convex surfaces 

 of both eyebrows." It can be ascertained by laying the smaller 

 metallic slide across the eyebrows, and drawing a line with red 

 pencil along its upper edge, or simply by turning the slide slightly 

 and pressing in the upper edge, so that it makes a slight depressed 

 mark in the skin. The mark will last long enough to enable the 

 measurement to be taken, and is perhaps more aocurate than a 

 pencil line. On the other hand, if a pencil line is made, the 

 measurement can be repeated with greater certainty. 



Height from vertex to chin. — This dimension is entered in column 

 29 of the register. It can, however, be most conveniently taken 

 immediately after the height from vertex to intersuperciliary point, 

 as the T — square is in exactly the same position throughout. Care 

 must be taken to read from the upper edge of the slide in measuring 

 the chin dimension. The lower edge gives the reading for the 

 intersuperciliary point if (as should be the oase) the sharp point 



