884 Notes and Memoranda. 



assistance of his own solar eye-piece, which permitted the use of a power of 400 

 to 600, he arrived at the conviction that the " brilliant objects were merely 

 different conditions of the surface of the comparatively large luminous clouds 

 themselves, ridges, waves, hills, knolls, or whatever else they might be called, 

 differing in form, in brilliancy, and probably in elevation, and bearing something 

 of the same proportion to the individual luminous clouds that the masses of the 

 bright facula?, as seen near the sun's edge, bear to the whole disc of the sun." 



The Companions of Sieitjs, Tkue and False. — Mr. Dawes states, in Monthly 

 Notices, that he has attained with his 8±-inch object-glass distinct views of 

 Alvon Clark's Companion of Sirius. Angle of position, 84° '86, distance about 

 ]0." Mr. Lassell and Mr. Marth have also observed it at Malta, their measures 

 of position ranged from 78°'53 to 80 3- 29, and their distances from 9"'21 to 10" - 90. 

 The little star appeared not a very small point, but deficient in brilliancy to 

 Mr. Lassell, and when Mr. Dawes first saw it, he turned round his object-glass 

 and eye-pieces to be certain it was a real star. His measures were only ap- 

 proximate. Mr. Tempel, of Marseilles, has a letter in the Astron. Nachrichten, 

 detailing his efforts to see the companions observed by M. Goldschmidt with a 

 telescope of about 4-inches. Mr. Tempel employed one of 48 lines, which he 

 says is a little bigger than M. Goldschmidt's, and of excellent performance on 

 double stars. With this instrument, after many hours' observation, he saw three 

 companion stars with magnifications of 40 and 24. He saw them less plainly with 

 60, and not at all with 80 and upwards. He saw similar appearances near 

 Procyon, Capella, and £ Orionis ; in the latter case, in addition to the true com- 

 panion. Careful experiment satisfied him that the appearances were false, and 

 that Goldschmidt had been deceived in assigning additional companions to Sirius. 



Size and Figure of the Eaeth. — The results obtained by our Ordnance 

 Survey exhibit the earth as having an equatorial semi-diameter of 20,927,005 feet, 



and a polar semi-axis of 20,852,372 feet. The flattening being 



260,4 -\- 8'3 



Comparing arcs of the meridian measured in England, France, Russia, Prussia, 

 Hanover, Denmark, and India, the Ordnance Survey gives for the average of the 

 globe — 



Semi-equatorial diameter, 20,926,330 feet. 



Semi-polar axis . . . 20,855,240 feet. 



Flattening — - — 



b 294,36 



The latter calculations take in the final determinations of the great Russian arc 

 measured by M. Struve. Tho French metre is thus not, as was supposed, ex- 

 actly a ten-millionth part of any ascertained quarter of a meridian, nor of an 

 average quarter meridian. 



Silkworms of tjie Oak. — M. Gucrin Mencville informs the French 

 Academy llmt, in addition to three Asiatic silkworms living on tho oak, tho 

 Jiombyx mrditla from Bengal, and Bombyx J'crnii from N. China, and Bonibyw 

 Tama- Mai from Japan, he is trying to naturalize a fourth, tho Bombvx Roylei, 

 from tin- Himalayas, on the borders of Cashmere. (>n the 28rd March ho 

 received 20 cocoons. At first only males won- prodnoed, but on the 19th April 

 he obtained a male and female moth, the latter laying 108 eggs, M. Menevllle 

 thinks it will be easy to rear these silkworms in Central and Northern France. 



I i lOTJOlTB of the Ci ii iu i mm. — Dr. Dickinson states that experiments 

 with reptiles and fish show t lint the cerebrum by itself IB unable to give more 

 than u limited amount of voluntary motion, and that of a kind deficient in balance 



and adjustment. If the cerebellum only be removed from fishes, there is a loss 

 of the proper adjustment between the right and left sides, so that oscillation or 

 rotation takes place. All the limbs are used, but apparently with a deficiency of 

 sustained activity. From the negative results of experiments it is inferred that 

 the cerebellum has nothing to Wo with common sensation, \\ il h tin- sexual pro- 

 by, with the action of the involuntary muscles, with the maintenance of 

 animal beat, OX with secretion. '1 be voluntary muscles aro under a double in- 

 llucnce, from tho cerebrum and tho cerebellum. Tho anterior limbs aro 



