1868.] Ml'. W. Hug-gins on a Hand Spectrum-Telescope. 241 



The eight skulls of Malays (six of men and two of women) afford the 

 highest mean of any of the Oceanic Kaces, viz. 47-07 oz., or 1334 grms. 

 For such a bold and enterprising race, who have pushed their migrations, 

 chiefly for commercial purposes, over almost the whole Ocean, such a rich 

 cerebral endowment might have been in some measure expected. 



The collection which has afforded the materials for this Memoir is rich 

 in crania from the Dutch dominions in the East-Indian Archipelago. 

 These are distinguished for a tolerably high average of brain-weight. And 

 this is not much diminished when we reach the aboriginal inhabitants of 

 the Polynesian Islands and "Western Pacific. 



In conclusion, it is believed that this investigation has contributed much 

 more than any former one to define and to discriminate the brain- weights 

 of different human races. Hence it is hoped that it will be accepted as a 

 valid contribution to a most important subject. 



II. ^^Description of a Hand Spectrum-Telescope.'^ By William 

 HuGGiNs, F.R.S. Received December 19^ 1867. 



The instrument described in this paper was contrived in the summer of 

 1866, for the purpose of observing the specti'a of meteors and their trains. 

 The special suitability of this apparatus, as a hand-spectroscope, for the 

 examination of the spectra of the lights which may be seen about the sun 

 during the total solar eclipse of next year, induces me to offer a descrip- 

 tion of it to the Royal Society. 



The apparatus consists essentially of a direct-vision prism placed in 

 front of a small achromatic telescope. 



The achromatic object-glass marked a is 1-2 inch in diameter, and 

 has a focal length of about 10 inches. The eyepiece {h) consists of 

 two plano-convex lenses. As a large field of view is of great importance, 

 especially for its use as a meteor-spectroscope, the field-lens is made of 

 nearly the same diameter as the object-glass. The imperfect definition at 

 the margin of the field is not of much practical importance, as the spectra 

 can be brought for examination into the centre of the field. The field- 

 lens is fixed in a sliding tube, which permits the distance between the two 

 lenses of the eyepiece to be altered ; in this way the magnifying-power of 

 the instrument may be varied within certain limits at pleasure. Be- 

 fore the object-glass is fixed a direct-vision prism (c), consisting of one 

 prism of dense flint glass, and two prisms of crown glass. 



The field of view of my apparatus embraces an area of sky of about 7° 

 in diameter. The spectrum of a bright star has an apparent length of 

 nearly 3°, The speetrum of the Great Nebula in Orion appears as two 



