PAPERS READ AT THE NATIONAL ACADEMY OF SCIENCE. 547 
wess in their respective fields. Prof. Henry Draper’s photographs of the nebulze 
of Orion must also be mentioned as contributions of the highest significance in 
physical astronomy, although not ranking, perhaps, with his brilliant discoveries 
from study of the solar spectrum. The objective lens with which this remarkable 
feat in photography was accomplished, was one of four which were manufactured 
according to a formula devised by Mr. Lewis M. Rutherford, of this city. It was 
originally manufactured to order for the Portuguese Government, and Mr. Ruth- 
erford was decorated a Knight of the Order of St. Ignacio in rcognition of his 
services. It differs from ordinary telescopic objectives in forming the image 
from the rays employed in photographing, not from those that are transmitted to the 
eye by a lens of the common pattern. Without this lens it would be impossible 
to obtain a photograph of the nebule of Orion. ‘The several memoirs of Prof. 
Agassiz have dealt, in one way or another, with the results obtained by the last 
expedition of the steamer Blake, of the United States Coast and Geodetic Sur- 
vey. As JVature for September 30 remarks, the work performed by the Coast 
Survey has received too little attention from the scientific classes in this country, 
and its brilliant results are but vaguely appreciated. An official report of the 
work done by the Blake under the superintendence of the Hon. Carlile P. Patter- 
son, not, however, embracing its results in natural history, has recently gone 
through the government printing office at Washington. It was prepared by Lieu- 
tenant Commander Charles D. Sigsbee, of the Blake, to whose invention and fer- 
tility of resources the expedition owes a large part of its success. The work of 
the Bibb and Hassler, which preceded the Blake in this field, has been rendered 
familiar to naturalists through the memoirs of the late Count Pourtales; but the 
biological observations more recently obtained by the Blake have not yet been 
rendered fully accessible. They are in course of publication under the direction 
of Prof. Agassiz, but only a part of the series has yet appeared. The memoir of 
Prof. Marsh on the dimensions of the brain and spinal cord in extinct reptiles, as 
compared with living representatives of the same genera and species, and Prof. 
Ogden N. Rood’s extraordinary paper on high vacua, must also be reckoned as 
contributions of which American scientists may well speak with pride. On the 
whole, the volume of transactions for 1880 will compare favorably with any pre- 
ceding volume since the National Academy of Sciences was founded, and will be 
sought with avidity and treasured with solicitude by the ablest representatives of 
science in Europe as well as in the United States. There has been absolutely no 
padding in the papers read; few have exceeded twenty minutes in delivery ; the 
majority have occupied not more than ten or fifteen minutes. 
The first paper on the list was by Prof. Henry Draper, on ‘‘ Photographing 
the Nebule of Orion,” the text of which was as follows: ‘‘ The gaseous nebu_ 
lee are bodies of interest, because they may be representing an early stage in the 
genesis of stellar or solar systems. Matter appears to exist in them in a simple 
form, as indicated by the simple spectrum of three or four lines. It is desirable, 
therefore, to ascertain what changes occur in the nebulz, and to determine, if 
