Serial aerologic observations with permanent character began in Havana on January 22, 1926, and although they never ended up being made daily, at that time they reached certain regularity. In that first year 95 soundings were made that increased to 182 in 1929 (Tabío, 1936).
The launchings were made initially at 07:00 hr., although later it was necessary to transfer the observation to 09:00, due to the presence of sectors of fog in the vicinity of the station. Results were analyzed also keeping in mind the regular nephologic observations taken every two hours, from 06:00 hr. until 18:00 hr.
The technique applied at the Observatory was based on the employment of a single globe, which demanded the exact calibration of the Hydrogen filling scale, previously adjusted and compared with the certified official standards from the USWB. The mean ascendant speed was estimated in about 3 m.s—1.
The optic team consisted on a theodolite built ad hoc by the house Buff & Buff, of Boston, United States of America, under contract of production requested by the Company of Scientific and Electric Materials of Havana. This instrument possessed a potent objective of 75mm and a folded ocular.
There were globes of two colors: “natural rubber” for clear sky, and red rubber for partially cloudy sky, also manufactured in the United States according to model settled down by the U. S. Army Signal Corp. With the purpose of elevating the degree of contrast, a red filter was added to the ocular of the theodolite (Millás, 1926).
The globes were observed from the roof of a construction of small size called “Meridian room” that was located in the place occupied today by the garden that separates the current building of the Center of Forecast at the Institute of Meteorology and the old Building of Aerology. The results of the optic observations were transmitted by internal phone circuit to the meteorologist in charge of plotting the positions on a celluloid disk whose result allowed establishing the trajectory of the globe and the direction of the wind at different levels.
For the realization of the soundings, the Observatory had the personal collaboration and the methodological advice of Dr. Cs. Charles Marvin, at the time Chief of the USWB. To professor Marvin’s interest is also due the shipment of the scale to adjust the weight of the globe and its relationship with the volume of gas needed to inflate it, as well as the drawing board necessary for the plotting of the successive positions of the globe. For the filling of the spheroid, Millás used a procedure well-known as “of defined inflation” (loc. cit.).
Engineer Millás had attentively studied the work entitled Instructions for Aerological Observers, edited by a community of authors among which Dr. Willis Gregg was, at the time chief of the aerologic service of the USWB, as well as the paper of R. C. Lane A Simple Filling Apparatus for Definite Inflation of Pilot Balloons, published on The Monthly Weather Review, in their edition corresponding to September of 1921.
The observations carried out in Havana were compared, whenever it was possible, with other soundings carried out at aerologic stations of the Caribbean area and the South of the United States, as those located in San Juan (Puerto Rico), Kingston (Jamaica) and Willemstead (Curazao) (loc. cit.).
An unequivocal test of the importance reached by the aerologic soundings in Cuba, is the inclusion of this topic in the program of the first course for meteorological observers imparted in the National Observatory.
A new step, of supreme importance, took place two decades later when the launching of globes equipped with radiosondes began to be carried out. But this will be the subject of the second part of this work.
The Author wishes to state his gratefulness to Israel Borrajero for his careful translation of this paper into English.
Note:
Whenever hourly data appear, they are referred to the local time for Havana City. The official unique hour for the whole country was established on 1925.
Figure 1. Engineer José C. Millás observing the direction of the clouds in the Finemann nefoscope. National Observatory (1936).
Figure 2. The place from which the launching of pilot globes was made is signaled with an arrow. The building at the bottom is currently the center of Forecast of the Institute of Meteorology. It was the National Observatory in 1926.
Figure 3. The "Meridian Room" of the National Observatory (1935). On the roof it was located the pedestal of the theodolite for the follow up of pilot globes.
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Figure 4. Theodolite Buff & Buff with objective of 75 mm. The bent ocular is observed in the first plane. |
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Figure 5. Aerologic scale sent to the National Observatory by Prof. Charles Marvin (from the USWB) for the filling of the pilot globes (1926). |
