TO CORRESPONDENTS. 



Extreme occupation during the concluding month of the 

 year has prevented my searching into the authorifias upon 

 which De Lalaode has established his comparison of the 

 English and French measures, and also those from which 

 he has deduced the measures of the earth's radii. I shall pay 

 attention to the request of " A Constant Reader" in the next 

 Number. 



Mr. Walker's letter from Oxford arrived by the post ; 

 but not the pamphlet. 



In answer to the inquiry of D. M. respecting a method of 

 cleansing linen by the application of steam, as used by the 

 French, I cannot point to any authentic account of a simple 

 process of this kind, though I have been informed that the 

 application of steam to piece goods, in a large digester, at a 

 temperature considerably above 212°, is very effectual in 

 cleansing, and promoting the bleaching process. This, how- 

 ever, seems fitter for the manufactory than the laundry. I 

 am disposed to think that the method alluded to by D. M. is 

 the Salzburg method, described in Van Mons's Journal, of 

 which a translation is given at p. 127 of the tenth volume of 

 our Journal, containing particular instructions how to carry 

 it into effect. 



I am sorry that a note of R. L. Edgworth, Esq. was not 

 noticed earlier. Four lines from the bottom of page 82 of 

 the last volume, the following should be inserted: "The 

 number of teeth necessary for the wheel may be easily cal- 

 culated to suit the measurement ; so that the dial-plate may 

 shew with sufficient accuracy five, or any other small number 

 of miles." 



Mr. R. L. E. speaks with commendation of Mr. Gilpin's 

 crane in that volume ; but remarks, that the groove which 

 renders a common chain so much preferable to a rope for 

 heavy burdens supported by tackles, has been long used. 



I have just received the work of the Rev. P. Roberts. 

 A..B. 



Dr. Bardsley, Physician to the Manchester Infirmary, 

 has committed to the press a Selection of the Reports of 

 Cases, Observations, and Experiments, chiefly derived from 

 Hospital Practice ; including, among others, Clinical Histo- 

 vies of Diabetes (with Chemical Experiments on the Nature 

 of diabetic Urine), Chronic Rheumatism, and Hydrophobia. 



