objection in its counter-affidavit that the experience in the said three institutions would not be considered. The four certificates produced by the 1st respondent are referred to at paragraph 6 of the counter-affidavit. The certificates indicated with the numbers 1, 2, 3 and 4 at paragraph 6 of the counter-affidavit are Exts P6, P8, P7 and P5 respectively. Objection is taken in the counteraffidavit only against Ext P5. It is contended in the counteraffidavit, at paragraph 6, that the first three certificates (Exts P6, P8 and P7 respectively) do not satisfy the prescribed three years' experience. The contention is correct. For, those three certificates take in only a total period of one year, four months and 23 days in different spells. The length of experience certified in Ext P5 is two years, one month and seven days. If Ext P5 is also taken into account, three years' experience is satisfied; to be precise, three years and six months. According to the appellant, Ext P5 cannot be considered for counting three years' experience.