11 



Sample of a post-card sent post free and used for reporting 

 an observation. 



Pofl'Smenlea or. 189?. cvi 76.788. sziimd kereskedelcmiieyi minisztcri rcndelct 



Magyar 



Ornithologiai Kozpont 



BUDAPEST 



VIII, Nemzeti Muzeuin. 



Obverse: 

 To the Hungarian Central Office of Ornithology 



Budapest. 

 Reverse : 



Chimney-swallow - - Hirundo rustica 

 Spring 1898. first swallow arriving : 



At extravillan . 



At intravillan 



At the house 



Breeding . . 



Datum 



N. N. 



County 

 District 



The indications supplied by these cards were subsequently turned 

 into elements. The annexed map shows the distribution of obser- 

 ving stations in 1898. 



Each dot indicates a locality, the geographical and hypso- 

 metrical position and the observer, and is therefore a complete 

 element . 



The network was close, but not quite even, because the 

 Saxons and Rumanians did not take part; also Croatia stood aloof. 



Upon receipt of these post-cards the information supplied was 

 turned into elements, by determination of the latitude, longitude, 

 and altitude, then arranged according to dates and each day 

 schematized on a specially prepared map of Hungary in its respec- 

 tive square. Thus 54, or rather 56 day-maps were prepared and 

 the number of dots entered showed exactly the beginning, the 



2* 



