Bottleneck

Bottleneck is a term that is used metaphorically and physically. Theconcept of bottleneck is related to controlling the flow of fluid (milk/water). The design of a vessel is made such a way so that the flow of the fluid may be controlled. “As water is poured out of a bottle, the rate of outflow is limited by the width of the conduit of exit—that is, bottleneck.”
(Ref. http://en.wikipedia.org/wiki/Bottleneck ; Oct. 4, 2012)

Plate 6A Hour-glass	6B Wider Passage	6C Earthen Pot (Matka)	6D&6E Carrying with water

(Source: http://www.google.co.in/search?hl=en&q=bottleneck&bav=on.2,or.r_gc.r_pw.r_qf.&
biw=1366&bih=664&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=vWVtUNHE
GpHJrAfJx4HgBw ; Oct. 4, 2012
Plate 6C-D: http://www.google.co.in/search?hl=en&q=bottleneck&bav=on.2,or.r_gc.r_pw.r_qf.&
biw=1366&bih=664&um =1&ie=UTF-8&tbm=isch&source=og&sa=N&tab=wi&ei=vWVtUNHEGp
HJrAfJx4HgBw#um=1&hl=en&biw=1366&bih=664&tbm=isch&sa=X&ei=z2tktUJXWKsXZrQe3_Y
CwDA&spell=1&q=Carrying+earthen+pot+on+waist&ved=0CD8QBSgA&bav=on.2,or.r_gc.r_pw.r
_qf.&fp=346d726c61c72844 ; Oct. 4, 2012