Regarding the delicate case of priority of investigation. Quotes example of Henry Warburton and John Brinkley.

Further regarding the Gregorian calendar and comments on some of the questions involved in its interpretation.

Would he drop him a few lines on the orbit of the meteor for the R.A.S. Robert Potts of Trinity is to publish by subscription a translation of Robert Simson's Porisms.

Has never heard the polar axis approximation. JH's treatise on perspective must be very complete. John Taylor is his old publisher. Has got 64 more syllogisms symbolized.

Guessed the name of his friend. Has not read the article attentively yet. If JH is in the south of France he may meet H. P. Brougham (Baron Brougham and Vaux) opticizing. Picked up an old book on the reformation of the calendar owned by C. Clavius 1556. Has sent to Rome for signature.

Raises a question regarding the size of an infinitely small quantity. Argues that 1850 is the last year of the first half of the nineteenth century.