Typographical Errors and Hints

The Sketch of the Analytical Enigine.. uses some typgraphical conventions not common today, and there are a few apparent typographical errors.

It is available as a facsimile unter archive.org (processed version removing the background: menabrea_lovelace1842_analyticalengine.pdf) and has been typeset anew in several places, e.g. in Charles Babbage and his CALCULATING ENGINES, edited by Philip and Emily Morrison, Dover Publications 1961, and online at http://fourmilab.ch/babbage/sketch.html. All contain typographic errors (pagenumbers refer to the original publication):

• Instead of nested parenthesis, parts of equations are overbarred instead, e.g. (4.) on page 716
• In the first equations of Note E (p.712), most reprints correctly use the upper index '1' instead of the prime as in the original; the equations referred to are not on p.679, but on p. 684
• In Note E p.714, equation 3, there is missing a cos in the second term of the right hand side; the formula should read (see page 723):

`cos n theta * cos theta = 1/2 cos [(n+1) theta] + 1/2 cos [(n-1) theta]`

• In the final table ending Note G, in operation 4, the operands have to be exchanged: V₄ has to be divided by V₅
• In the same table in line 21, it must read ²V₁₂ instead of ⁰V₁₂ in the result column
• In operation 24, the negative value of V₁₃ has to be transferred to V₂₄, i.e. V₂₄-V₁₃ must be calculated, and in the 6^th column read =-B₇
• Also in the same line, in the (forth to last) column for V₁₃ the digit zero must printed, as is given in the 5^th column, according to the rule that intermediate variables have to be to set to zero finally.

Note that in line 25 in the result column and in the next one right to the equals sign should read ²V₃ instead of ¹V₃; however AAL argued that the upper index is correct, as this value is for the next round of calculations, and thus must have the upper index 1 for a starting value.