The serious defects of the cross-staff, popular although it was with sailors, were often pointed out by English mathematicians, They were also critical of the current navigating manuals, and of the maritime chart.
Imiphumelo ebalulekileyo yokunqumla kwesitafu yabaninzi nangona yayikurhwebo ngeenqanawa babekhombe kwabezibalo abangama Ngesi babengxeka ngokuba nencwadi zohamb ngenqanawa netshati zokuhambisa ngeenqanawa.