Simile of the day: Flow into like batter flowing into the grooves of a waffle iron

In “The Measure of Manhattan” (W.W. Norton, $26.95), Marguerite Holloway offers up a  biography of  John Randel Jr.,  the man y who codified Manhattan’s street grid early in the 19th century,   As  Professor Holloway explains the  response to that  new  street organization as follows:

New York City flowed into that form, like batter flowing into the grooves of a waffle iron.