NO. 7 



THE PYRANOMETER ABBOT AND ALDRICH 



considerable extent avoided in the sixth form, of which more will be 

 said hereafter. 



A and B are strips of manganin, each exposing surfaces 6 mm. 

 long and 2 mm. wide. The strips are bent through 45° at the ends 

 of the exposed portion and soldered with great care on to the lower 

 parts of the split copper blocks C, C^, D, D^, in such manner that the 

 solder goes exactly to the bend where the manganin strip becomes 



exposed. The strips A, B, are situated in the center of the polished 

 nickel-plated copper block E and are separated the one from the other 

 by the copper strip F. Electrical insulation between the strips A, B 

 (with their attached copper blocks C, O, D, D^), and the plate E 

 and strip F are provided by means of thin vertical separating strips 

 of mica, coming exactly to the common surface of the plate E and 

 manganin strips A, B. Conductors (not shown) run from the blocks 

 C, O, D, D^, to the switch H, and thence to the pair of binding posts 

 G, of w^hich only one of the two appears in figure i. Between the 



