112 Mr Glaisher, On factor tables. [Feb. 11, 



He states that he has made arrangements with Rosenthal, of 

 Nordhausen (a baker by trade, but who has written one or two 

 small books), to halve the remainder of the work, von Stamford 

 undertaking the portion from 504,000 to 750,000, and Rosenthal 

 the remainder from 750,000 to 1,000,000. The next two letters, 

 von Stamford to Lambert, July 23, 1775, and Lambert to von 

 Stamford, August 12, relate chiefly to a method of Kastner's for 

 computing logarithms, and but slight mention is made of the 

 factor table. In a letter without date, but written towards the 

 end of February, 1776, Lambert, not knowing the address of von 

 Stamford, writes to Rosenthal to ask him the state of the work, as 

 he has unexpectedly received from Felkel at Vienna an announce- 

 ment relating to a machine for readily finding factors, and to a 

 factor table from 1 to 144,000. Lambert states that Felkel intends 

 to extend his table to 1,000,000, and that he (Lambert) has 

 written to tell him of the work in progress ; he hopes that Felkel 

 will begin at 1,000,000 and continue the table from 1,000,000 to 

 2,000,000, and that the whole two millions may appear together. 

 This he has proposed to Felkel, who appears to agree to it. 

 Rosenthal's reply is dated March 6. He says that on February 

 2 von Stamford wrote to him to say that on account of his health 

 he could not complete his part of the factor table, and asking 

 Rosenthal to undertake the whole of the remainder. Rosenthal 

 had replied in the afiirmative on February 14. As for his own 

 work (which he describes as 725,000 to 1,000,000) he is so far ad- 

 vanced that he could, with the aid of a factor table to 143,000, 

 complete it in two months : he hopes that Felkel wall agree to a 

 joint publication. 



The remaining two letters are from Lambert to Rosenthal. 

 The first (July 30, 1776) shows considerable irritation against 

 Felkel. Lambert says that Felkel has only accepted his sugges- 

 tion as far as serves his own purpose. That he can find in him no 

 trace of confidence, modesty, or fairness ; that he asks him to 

 approve of a work that he has not seen, and to obtain sub- 

 scribers, when the whole affair may be only boasting. He tells 

 Rosenthal it is useless for him to extend the table further at 

 present. In a note to this letter Bernoulli adds that a friend of 

 his who had formed aa unfavourable impression of Felkel from 

 his publications, changed his opinion when he knew him per- 

 sonally, and that very likely Lambert would have done the same. 

 The second letter (August 13, 1776) announces a new event, 

 viz. that Hindenburg, of Leipzig, having seen an advertisement of 

 Felkel's undertakiag, had announced a factor table to five millions, 

 which however was only to give the least factor. Lambert suggests 

 that it would be better if the one would begin where the other left 

 off, and wonders whether any more factor tables will be an- 



