SCIENCE. 



[Vol. I., No. 1. 



isobiiric lines is strongly in favor of the theory 

 of converging winds, and appareuth' fatal to 

 that of the long-held one of circular winds. 



Vortex. —At 11.46 a.m. (20th), after a 

 violent rush from the west-north-west, Manila 

 was in the vortex. The calm was not abso- 

 lute, but with alternate gusts and lulls for 

 about eight minutes; at 11.52 the calm was 

 absolute for two minutfes ; then alternate calm 

 and gusts from the south-west. Blue sky was 



dows during the calm were instantly com- 

 pelled to close them, for the air ' burned ' as 

 in the Italian sirocco. 



Barometer. — The lowest barometer was at 

 11.40, or 6 minutes before entering the rela- 

 tive, and 10-12 before the absolute, calm ; at 

 this time Manila was probably the nearest to 

 the centre of the vortex. At 11.54 it began 

 to rise rapidly, the wind changing suddenly to 

 the south-west, but with equal violence. The 



MAP SHOWING THE COURSE OP THE HURRTCANT:, AND THE DISTRIBUTION OF THE ISOBARIC LINES AROUND THE CENTRE. 



1. — Bay of CaBiguran. 2. — Island of Polillo. 3. — Catanduanes Islands. 4. — Strait of San Bernardino. 5. — Island of Sibuyan. 

 6. — Island of Romblon. 7. — Island of Tablas. 8. — Island of Burias. 9. — Island of Marinduque. 10. — Calamianes Islands. 

 11. — Island of Luban. 12. — Bay of Manila. The large arrow indicates the course of the hurricane, and horizontal section of 

 the same, as it passed over Manila. 765 to 727 mm. (29.45-28.35 in.) the fall of the barometer. 



not seen, but it cleared to a dense watery 

 vapor ; the dark belt of the storm could be 

 traced on the horizon. The diameter of the 

 vortex was probably not more than 14 or 16 

 miles. 



Changes. — The most striking phenomenon 

 was the sudden change of temperature and 

 hj'grometric condition of the air, as revealed 

 by the curves traced ; the former from 75° 

 to 88° F., and the latter from 53 (rarely ob- 

 served here, and onlj' iftr April and May) up 

 to saturation. Persons who opened their win- 



blow lasted 2^ hours ; and its traced fury for 

 the last half of the diagram was estimated, but 

 not observed for want of instruments. 



At 12.30 the dense clouds began to rise 

 quickl}^ indicating that at the posterior part of 

 the storm the winds had also mounted higher. 

 It was peculiarlj' destructive, as Manila was 

 exactly at the point of this sudden change of 

 elevation. 



Force. — The observatory is about 113 feet 

 above sea-level. Just before 11 a.m. the 

 wind tore up a palma brava some 1,000 feet 



