390 Proceedings of the 



March, January, April, November, September, December, October, 

 May, August, June, July : counting backwards for nine months, we 

 have the following order as that of the conceptions, May, June, 

 April, July, February, December, March, January, August, November, 

 September, October. It will be observed, that the months in which 

 the greatest number of conceptions take place are not those in which 

 there are the greatest number of marriages, which proves that con- 

 ception rarely takes place in the first month of marriage ; on an 

 average it attains its maximum about two or three months after- 

 wards. The greatest number of conceptions are in spring and sum- 

 mer, and the smallest number in autumn and winter ; but M. ,Giroux 

 imagines that this is not so much owing to the direct influence of 

 the seasons, as to the fact of each season bringing periodically the 

 recurrence of labours and habits more or less favourable to the 

 procreative power. Thus it appears that the greatest number of 

 conceptions are in those months in which the strength of man is 

 developed by exercise and moderate labour ; and the smallest num- 

 ber at the period of the dispersion and emigration of the rural 

 population, and of the recurrence of more fatiguing labour. The 

 greatest number of boys are born in January and June, the greatest 

 number of girls in December and July ; whence the maximum of 

 the conception of the former is in April and September, and of the 

 latter in March and October. M. Giroux is of opinion that the 

 female sex predominates in first conceptions. The greatest number 

 of natural children are born in the months of February, March, 

 January, and April, and are, consequently, conceived in the months 

 of May, June, April, and July ; the same as has been observed of 

 legitimate children. But the smallest number of births of natural 

 children is in the months of July, August, September, and October ; 

 and, consequently, the smallest number of conceptions is in the 

 months of October, November, December, and January, being two 

 months further advanced in the cold season than the minimum of 

 conception of legitimate children. The greatest number of boys 

 among natural children are born in January and July, and of girls 

 in November and December ; consequently, the most numerous con- 

 ceptions of the former are in April and October, and of the latter in 

 February and March. M. Giroux has confirmed these general calcu- 

 lations, by applying them to each department separately, and finds 

 the results nearly similar. The reporter concluded by recommending 

 M. Giroux to persevere in his researches after new facts to verify 

 and confirm the results at which he has arrived. 



Wooden Houses. On the 19th September, M. Navier made a 

 report on a memoir by M. Blom, a colonel of engineers in Sweden, 

 relative to moveable wooden houses constructed by him. A report 

 on a former memoir of M. Blom had been made last year by MM. 

 Navier, de Prony, and Girard, in which it was suggested that the 

 invention, although well adapted for cold countries, would be found 



