June, 192o. I CURRENT TOPICS. 8 1 7

The Production of Power from Blast Furnace Gas. S . H . FOWLES. (Electrician, M a r c h 26, I 9 2 O . ) 7 S i r C h a r l e s A. P a r s o n s , F r a n k l i n meda l l i s t , " has e s t i m a t e d t h a t t he t o t a l a v a i l a b l e w a t e r - power in the Br i t i sh Isles is only I ~ mil l ion horse -power , and that E n g l a n d possesses only one pe r cent. of the w a t e r - p o w e r and 2 ½ per cent. of the total coal in the wor ld . " T h e b l a s t f u r n a c e s of Grea t Br i t a in annua l ly waste a mil l ion horse -power . The fol low- ing t a b l e c o m p a r e s the o ld m e t h o d w i t h t he H a l b e r g - B e t h t y p e of p l a n t :

Old Method Gas made per furnace per hour . . . . . . . . . . . . . I,ooo,ooo cu. ft. Gas used per furnace per hour . . . . . . . . . . . . . I,OOO,OOO cu. ft. Coke per ton of pig iron made . . . . . . . . . . . . . . . 23 cwt. Units of electricity generated per furnace per

annum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . None 6,87o,ooo Potash saved per ammm . . . . . . . . . . . . . . . . . . . None £6,000 Flue cleaning costs per ammm . . . . . . . . . . . . . . £I,ooo None Coal used per furnace per hour . . . . . . . . . . . . . o.5 ton o.2 ton Horse-power developed per furnace per hour 6oo 8o0

G. F . S.

New Method I,OOO, OOa CU. [~.

550,00o cu. ft. 2I cwt .

Heat production during luminescence has been s t u d i e d b y E. NEWTON F ,grEY (Journal of General Physiology, I919, ii, i 3 7 - I43 ) . Cypric ct hilgendorfi, a small c rus tacean, contains a com- p o u n d lucifer .n~ and an e n z y m e luc i fe rase , w h i c h o x i d i z e s the luc i f e r in to o x y l u c i f e r i n in the p r e s e n c e of w a t e r and o x y g e n ; th i s r e a c t i o n is a c c o m p a n i e d b y the p r o d u c t i o n of l i gh t , and is the cause of the b i o l u m i n e s c e n c e of the l i v i n g a n ima l . B o t h the luc i fe r in and the l uc i f e r a se a re so lub le in w a t e r ; a n d a solutioI1 m a y be p r e p a r e d c o n t a i n i n g on ly one o r the o t h e r of the t w o s u b s t a n c e s . A s o l u t i o n of luc i fe r in w a s m i x e d w i t h one of lucif- e r a se in a s u i t a b l e a p p a r a t u s , and the c h a n g e in t e m p e r a t u r e no ted . T h e r e s u l t s i n d i c a t e d t h a t I g r a m of luc i fe r in l iberates less than o. i small calorie du r ing the luminescence which accom- panies its ox ida t ion .

J.S.H.

Duration of Light Emission from a Radiating Hydrogen Atom. A. jr. DEMPSTI'2R. (Physical Review, F e b r u a r y , 192o. ) - Cana l r a y s w e r e sho t t h r o u g h a hole f rom a d i s c h a r g e t u b e in to a s e c o n d t ube w i t h a m u c h h i g h e r v a c u u m . A f t e r m o v i n g a b o u t 4 cm. b e y o n d the hole t he l u m i n o s i t y of t h e p a r t i c l e s d ied out . F r o m the D o p p l e r effect e x h i b i t e d b y the r a y s the s p e e d of the p a r t i c l e s was f o u n d to be 9o,ooo, ooo cm. pe r second. Hence the t ime re- qu i r ed for the l i g h t to die a w a y b e y o n d the hole w a s a b o u t five h u n d r e d - m i l l i o n t h s of a second . T h e l i gh t was chief ly t h a t of the be t a l ine of h y d r o g e n .

G. F. S. VOL. I89, No. I t 3 4 - - 5 8